[Scummvm-git-logs] scummvm master -> ba8551b3aecc876158e3dfd8b66407efb5b7c4e5

[criezy]

This automated email contains information about 2 new commits which have been
pushed to the 'scummvm' repo located at https://github.com/scummvm/scummvm .

Summary:
4ced49acd4 ENGINES: Changed AdvancedMetaEngine::createInstance to return a Common::Error
ba8551b3ae AGOS: Allow detecting games from disabled subengines


Commit: 4ced49acd496133852c42f3297e25cb669882838
    https://github.com/scummvm/scummvm/commit/4ced49acd496133852c42f3297e25cb669882838
Author: Cameron Cawley (ccawley2011 at gmail.com)
Date: 2020-12-04T20:57:14Z

Commit Message:
ENGINES: Changed AdvancedMetaEngine::createInstance to return a Common::Error

Changed paths:
  A engines/cryomni3d/POTFILES
    engines/access/metaengine.cpp
    engines/adl/metaengine.cpp
    engines/advancedDetector.cpp
    engines/advancedDetector.h
    engines/agi/metaengine.cpp
    engines/agos/metaengine.cpp
    engines/avalanche/metaengine.cpp
    engines/bbvs/metaengine.cpp
    engines/bladerunner/metaengine.cpp
    engines/cge/metaengine.cpp
    engines/cge2/metaengine.cpp
    engines/chewy/metaengine.cpp
    engines/cine/metaengine.cpp
    engines/composer/metaengine.cpp
    engines/cruise/metaengine.cpp
    engines/cryo/metaengine.cpp
    engines/cryomni3d/metaengine.cpp
    engines/director/metaengine.cpp
    engines/dm/metaengine.cpp
    engines/draci/metaengine.cpp
    engines/dragons/metaengine.cpp
    engines/drascula/metaengine.cpp
    engines/dreamweb/metaengine.cpp
    engines/gnap/metaengine.cpp
    engines/gob/metaengine.cpp
    engines/griffon/metaengine.cpp
    engines/grim/POTFILES
    engines/grim/metaengine.cpp
    engines/groovie/metaengine.cpp
    engines/hadesch/metaengine.cpp
    engines/hdb/metaengine.cpp
    engines/hopkins/metaengine.cpp
    engines/hugo/metaengine.cpp
    engines/icb/metaengine.cpp
    engines/illusions/metaengine.cpp
    engines/kingdom/metaengine.cpp
    engines/kyra/metaengine.cpp
    engines/lab/metaengine.cpp
    engines/lastexpress/metaengine.cpp
    engines/lilliput/metaengine.cpp
    engines/lure/metaengine.cpp
    engines/macventure/metaengine.cpp
    engines/made/metaengine.cpp
    engines/mads/metaengine.cpp
    engines/mohawk/POTFILES
    engines/mohawk/metaengine.cpp
    engines/mortevielle/metaengine.cpp
    engines/mutationofjb/metaengine.cpp
    engines/myst3/metaengine.cpp
    engines/neverhood/metaengine.cpp
    engines/ngi/metaengine.cpp
    engines/parallaction/metaengine.cpp
    engines/pegasus/metaengine.cpp
    engines/petka/metaengine.cpp
    engines/pink/metaengine.cpp
    engines/plumbers/metaengine.cpp
    engines/prince/metaengine.cpp
    engines/queen/metaengine.cpp
    engines/saga/metaengine.cpp
    engines/sci/metaengine.cpp
    engines/sherlock/metaengine.cpp
    engines/sludge/metaengine.cpp
    engines/stark/metaengine.cpp
    engines/startrek/metaengine.cpp
    engines/supernova/metaengine.cpp
    engines/sword25/metaengine.cpp
    engines/teenagent/metaengine.cpp
    engines/testbed/metaengine.cpp
    engines/tinsel/metaengine.cpp
    engines/titanic/metaengine.cpp
    engines/toltecs/metaengine.cpp
    engines/tony/metaengine.cpp
    engines/toon/metaengine.cpp
    engines/touche/metaengine.cpp
    engines/tsage/metaengine.cpp
    engines/tucker/metaengine.cpp
    engines/twine/metaengine.cpp
    engines/ultima/metaengine.cpp
    engines/ultima/metaengine.h
    engines/voyeur/metaengine.cpp
    engines/wage/metaengine.cpp
    engines/wintermute/metaengine.cpp
    engines/xeen/metaengine.cpp
    engines/zvision/metaengine.cpp


diff --git a/engines/access/metaengine.cpp b/engines/access/metaengine.cpp
index 662c7e6617..3bfe4bdb17 100644
--- a/engines/access/metaengine.cpp
+++ b/engines/access/metaengine.cpp
@@ -76,7 +76,7 @@ public:
 
     bool hasFeature(MetaEngineFeature f) const override;
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -101,21 +101,19 @@ bool Access::AccessEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool AccessMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error AccessMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const Access::AccessGameDescription *gd = (const Access::AccessGameDescription *)desc;
-	if (gd) {
-		switch (gd->gameID) {
-		case Access::GType_Amazon:
-			*engine = new Access::Amazon::AmazonEngine(syst, gd);
-			break;
-		case Access::GType_MartianMemorandum:
-			*engine = new Access::Martian::MartianEngine(syst, gd);
-			break;
-		default:
-			error("Unknown game");
-		}
+	switch (gd->gameID) {
+	case Access::GType_Amazon:
+		*engine = new Access::Amazon::AmazonEngine(syst, gd);
+		break;
+	case Access::GType_MartianMemorandum:
+		*engine = new Access::Martian::MartianEngine(syst, gd);
+		break;
+	default:
+		return Common::kUnsupportedGameidError;
 	}
-	return gd != 0;
+	return Common::kNoError;
 }
 
 SaveStateList AccessMetaEngine::listSaves(const char *target) const {
diff --git a/engines/adl/metaengine.cpp b/engines/adl/metaengine.cpp
index daa38dfcf6..72409a86a1 100644
--- a/engines/adl/metaengine.cpp
+++ b/engines/adl/metaengine.cpp
@@ -79,7 +79,7 @@ public:
 	SaveStateList listSaves(const char *target) const override;
 	void removeSaveState(const char *target, int slot) const override;
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
 };
 
 bool AdlMetaEngine::hasFeature(MetaEngineFeature f) const {
@@ -209,10 +209,7 @@ Engine *HiRes4Engine_create(OSystem *syst, const AdlGameDescription *gd);
 Engine *HiRes5Engine_create(OSystem *syst, const AdlGameDescription *gd);
 Engine *HiRes6Engine_create(OSystem *syst, const AdlGameDescription *gd);
 
-bool AdlMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const {
-	if (!gd)
-		return false;
-
+Common::Error AdlMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const {
 	const AdlGameDescription *adlGd = (const AdlGameDescription *)gd;
 
 	switch (adlGd->gameType) {
@@ -238,10 +235,10 @@ bool AdlMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameD
 		*engine = HiRes6Engine_create(syst, adlGd);
 		break;
 	default:
-		error("Unknown GameType");
+		return Common::kUnsupportedGameidError;
 	}
 
-	return true;
+	return Common::kNoError;
 }
 
 } // End of namespace Adl
diff --git a/engines/advancedDetector.cpp b/engines/advancedDetector.cpp
index a6f0ef6b93..b4141e25a3 100644
--- a/engines/advancedDetector.cpp
+++ b/engines/advancedDetector.cpp
@@ -399,12 +399,10 @@ Common::Error AdvancedMetaEngineDetection::createInstance(OSystem *syst, Engine
 
 	if (plugin) {
 		// Call child class's createInstanceMethod.
-		if (plugin->get<AdvancedMetaEngine>().createInstance(syst, engine, agdDesc.desc)) {
-			return Common::Error(Common::kNoError);
-		}
+		return plugin->get<AdvancedMetaEngine>().createInstance(syst, engine, agdDesc.desc);
 	}
 
-	return Common::Error(Common::kNoGameDataFoundError);
+	return Common::Error(Common::kEnginePluginNotFound);
 }
 
 void AdvancedMetaEngineDetection::composeFileHashMap(FileMap &allFiles, const Common::FSList &fslist, int depth, const Common::String &parentName) const {
diff --git a/engines/advancedDetector.h b/engines/advancedDetector.h
index 14744d557c..a19fdab49b 100644
--- a/engines/advancedDetector.h
+++ b/engines/advancedDetector.h
@@ -448,7 +448,7 @@ public:
 	 * A createInstance implementation for subclasses. To be called after the base
 	 * createInstance function above is called.
 	 */
-	virtual bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const = 0;
+	virtual Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const = 0;
 
 	/**
 	 * Return the name of the engine plugin based on the engineID.
diff --git a/engines/agi/metaengine.cpp b/engines/agi/metaengine.cpp
index 3811371c8b..d91099f85c 100644
--- a/engines/agi/metaengine.cpp
+++ b/engines/agi/metaengine.cpp
@@ -112,7 +112,7 @@ public:
 		return "agi";
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -134,9 +134,8 @@ bool AgiMetaEngine::hasFeature(MetaEngineFeature f) const {
 		(f == kSimpleSavesNames);
 }
 
-bool AgiMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error AgiMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const Agi::AGIGameDescription *gd = (const Agi::AGIGameDescription *)desc;
-	bool res = true;
 
 	switch (gd->gameType) {
 	case Agi::GType_PreAGI:
@@ -151,9 +150,7 @@ bool AgiMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameD
 			*engine = new Agi::WinnieEngine(syst, gd);
 			break;
 		default:
-			res = false;
-			error("PreAGI engine: unknown gameID");
-			break;
+			return Common::kUnsupportedGameidError;
 		}
 		break;
 	case Agi::GType_V1:
@@ -162,11 +159,10 @@ bool AgiMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameD
 		*engine = new Agi::AgiEngine(syst, gd);
 		break;
 	default:
-		res = false;
-		error("AGI engine: unknown gameType");
+		return Common::kUnsupportedGameidError;
 	}
 
-	return res;
+	return Common::kNoError;
 }
 
 SaveStateList AgiMetaEngine::listSaves(const char *target) const {
diff --git a/engines/agos/metaengine.cpp b/engines/agos/metaengine.cpp
index 98655c22aa..58aca57e47 100644
--- a/engines/agos/metaengine.cpp
+++ b/engines/agos/metaengine.cpp
@@ -45,7 +45,7 @@ public:
 		Engines::upgradeTargetIfNecessary(obsoleteGameIDsTable);
 		return AdvancedMetaEngine::createInstance(syst, engine);
 	}
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -62,9 +62,8 @@ bool AGOS::AGOSEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsReturnToLauncher);
 }
 
-bool AgosMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error AgosMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const AGOS::AGOSGameDescription *gd = (const AGOS::AGOSGameDescription *)desc;
-	bool res = true;
 
 	switch (gd->gameType) {
 	case AGOS::GType_PN:
@@ -100,11 +99,10 @@ bool AgosMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGame
 		break;
 #endif
 	default:
-		res = false;
-		error("AGOS engine: unknown gameType");
+		return Common::kUnsupportedGameidError;
 	}
 
-	return res;
+	return Common::kNoError;
 }
 
 SaveStateList AgosMetaEngine::listSaves(const char *target) const {
diff --git a/engines/avalanche/metaengine.cpp b/engines/avalanche/metaengine.cpp
index 51ff2dea27..d02f110dec 100644
--- a/engines/avalanche/metaengine.cpp
+++ b/engines/avalanche/metaengine.cpp
@@ -60,7 +60,7 @@ public:
 		return "avalanche";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 
 	int getMaximumSaveSlot() const override { return 99; }
@@ -69,10 +69,9 @@ public:
 	SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const override;
 };
 
-bool AvalancheMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const {
-	if (gd)
-		*engine = new AvalancheEngine(syst, (const AvalancheGameDescription *)gd);
-	return gd != 0;
+Common::Error AvalancheMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const {
+	*engine = new AvalancheEngine(syst, (const AvalancheGameDescription *)gd);
+	return Common::kNoError;
 }
 
 bool AvalancheMetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/bbvs/metaengine.cpp b/engines/bbvs/metaengine.cpp
index ca070f4cac..2d8e0eae06 100644
--- a/engines/bbvs/metaengine.cpp
+++ b/engines/bbvs/metaengine.cpp
@@ -44,7 +44,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	int getMaximumSaveSlot() const override;
 	SaveStateList listSaves(const char *target) const override;
@@ -121,11 +121,9 @@ SaveStateDescriptor BbvsMetaEngine::querySaveMetaInfos(const char *target, int s
 	return SaveStateDescriptor();
 }
 
-bool BbvsMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new Bbvs::BbvsEngine(syst, desc);
-	}
-	return desc != 0;
+Common::Error BbvsMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Bbvs::BbvsEngine(syst, desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(BBVS)
diff --git a/engines/bladerunner/metaengine.cpp b/engines/bladerunner/metaengine.cpp
index 1a358b48c1..b467b5b71c 100644
--- a/engines/bladerunner/metaengine.cpp
+++ b/engines/bladerunner/metaengine.cpp
@@ -35,7 +35,7 @@ class BladeRunnerMetaEngine : public AdvancedMetaEngine {
 public:
     const char *getName() const override;
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 
 	SaveStateList listSaves(const char *target) const override;
@@ -48,10 +48,9 @@ const char *BladeRunnerMetaEngine::getName() const {
 	return "bladerunner";
 }
 
-bool BladeRunnerMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error BladeRunnerMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	*engine = new BladeRunner::BladeRunnerEngine(syst, desc);
-
-	return true;
+	return Common::kNoError;
 }
 
 bool BladeRunnerMetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/cge/metaengine.cpp b/engines/cge/metaengine.cpp
index ae9a613c28..c3c63051a6 100644
--- a/engines/cge/metaengine.cpp
+++ b/engines/cge/metaengine.cpp
@@ -39,7 +39,7 @@ public:
 
     bool hasFeature(MetaEngineFeature f) const override;
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	int getMaximumSaveSlot() const override;
 	SaveStateList listSaves(const char *target) const override;
@@ -153,11 +153,9 @@ SaveStateDescriptor CGEMetaEngine::querySaveMetaInfos(const char *target, int sl
 	return SaveStateDescriptor();
 }
 
-bool CGEMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new CGE::CGEEngine(syst, desc);
-	}
-	return desc != 0;
+Common::Error CGEMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new CGE::CGEEngine(syst, desc);
+	return Common::kNoError;
 }
 
 } // End of namespace CGE
diff --git a/engines/cge2/metaengine.cpp b/engines/cge2/metaengine.cpp
index bd3cdf68d7..336e52d2cb 100644
--- a/engines/cge2/metaengine.cpp
+++ b/engines/cge2/metaengine.cpp
@@ -39,7 +39,7 @@ public:
 		return "cge2";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 	int getMaximumSaveSlot() const override;
 	SaveStateList listSaves(const char *target) const override;
@@ -47,11 +47,9 @@ public:
 	void removeSaveState(const char *target, int slot) const override;
 };
 
-bool CGE2MetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc)
-		*engine = new CGE2::CGE2Engine(syst, desc);
-
-	return desc != 0;
+Common::Error CGE2MetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new CGE2::CGE2Engine(syst, desc);
+	return Common::kNoError;
 }
 
 bool CGE2MetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/chewy/metaengine.cpp b/engines/chewy/metaengine.cpp
index 1be80fe05a..1a55a79983 100644
--- a/engines/chewy/metaengine.cpp
+++ b/engines/chewy/metaengine.cpp
@@ -48,7 +48,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -74,12 +74,9 @@ bool Chewy::ChewyEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool ChewyMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Chewy::ChewyGameDescription *gd = (const Chewy::ChewyGameDescription *)desc;
-	if (gd) {
-		*engine = new Chewy::ChewyEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error ChewyMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Chewy::ChewyEngine(syst, (const Chewy::ChewyGameDescription *)desc);
+	return Common::kNoError;
 }
 
 SaveStateList ChewyMetaEngine::listSaves(const char *target) const {
diff --git a/engines/cine/metaengine.cpp b/engines/cine/metaengine.cpp
index 45447f58cf..98245aa175 100644
--- a/engines/cine/metaengine.cpp
+++ b/engines/cine/metaengine.cpp
@@ -54,10 +54,7 @@ public:
 		return "cine";
 	}
 
-    Common::Error createInstance(OSystem *syst, Engine **engine) const override {
-		return AdvancedMetaEngine::createInstance(syst, engine);
-	}
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	bool hasFeature(MetaEngineFeature f) const override;
 	SaveStateList listSaves(const char *target) const override;
@@ -86,12 +83,9 @@ bool Cine::CineEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool CineMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Cine::CINEGameDescription *gd = (const Cine::CINEGameDescription *)desc;
-	if (gd) {
-		*engine = new Cine::CineEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error CineMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Cine::CineEngine(syst, (const Cine::CINEGameDescription *)desc);
+	return Common::kNoError;
 }
 
 SaveStateList CineMetaEngine::listSaves(const char *target) const {
diff --git a/engines/composer/metaengine.cpp b/engines/composer/metaengine.cpp
index 8c7511dc69..7fdeaf8a09 100644
--- a/engines/composer/metaengine.cpp
+++ b/engines/composer/metaengine.cpp
@@ -71,19 +71,16 @@ public:
 		return "composer";
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 
 	int getMaximumSaveSlot() const override;
 	SaveStateList listSaves(const char* target) const override;
 };
 
-bool ComposerMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Composer::ComposerGameDescription *gd = (const Composer::ComposerGameDescription *)desc;
-	if (gd) {
-		*engine = new Composer::ComposerEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error ComposerMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Composer::ComposerEngine(syst, (const Composer::ComposerGameDescription *)desc);
+	return Common::kNoError;
 }
 
 bool ComposerMetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/cruise/metaengine.cpp b/engines/cruise/metaengine.cpp
index 5224d3bad1..06864f414e 100644
--- a/engines/cruise/metaengine.cpp
+++ b/engines/cruise/metaengine.cpp
@@ -56,7 +56,7 @@ public:
 	SaveStateList listSaves(const char *target) const override;
 	void removeSaveState(const char *target, int slot) const override;
 	SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 };
 
 bool CruiseMetaEngine::hasFeature(MetaEngineFeature f) const {
@@ -123,12 +123,9 @@ SaveStateDescriptor CruiseMetaEngine::querySaveMetaInfos(const char *target, int
 	return SaveStateDescriptor();
 }
 
-bool CruiseMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Cruise::CRUISEGameDescription *gd = (const Cruise::CRUISEGameDescription *)desc;
-	if (gd) {
-		*engine = new Cruise::CruiseEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error CruiseMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Cruise::CruiseEngine(syst, (const Cruise::CRUISEGameDescription *)desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(CRUISE)
diff --git a/engines/cryo/metaengine.cpp b/engines/cryo/metaengine.cpp
index 47a7bd1a2d..db6afe4612 100644
--- a/engines/cryo/metaengine.cpp
+++ b/engines/cryo/metaengine.cpp
@@ -42,18 +42,16 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 };
 
 bool CryoMetaEngine::hasFeature(MetaEngineFeature f) const {
 	return false;
 }
 
-bool CryoMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new Cryo::CryoEngine(syst, desc);
-	}
-	return desc != 0;
+Common::Error CryoMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Cryo::CryoEngine(syst, desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(CRYO)
diff --git a/engines/cryomni3d/POTFILES b/engines/cryomni3d/POTFILES
new file mode 100644
index 0000000000..da57a34418
--- /dev/null
+++ b/engines/cryomni3d/POTFILES
@@ -0,0 +1 @@
+engines/cryomni3d/metaengine.cpp
diff --git a/engines/cryomni3d/metaengine.cpp b/engines/cryomni3d/metaengine.cpp
index 42f830aecb..ad89db1ecb 100644
--- a/engines/cryomni3d/metaengine.cpp
+++ b/engines/cryomni3d/metaengine.cpp
@@ -74,7 +74,7 @@ public:
 	}
 
 	bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override { return 999; }
@@ -129,26 +129,21 @@ void CryOmni3DMetaEngine::removeSaveState(const char *target, int slot) const {
 	g_system->getSavefileManager()->removeSavefile(filename);
 }
 
-bool CryOmni3DMetaEngine::createInstance(OSystem *syst, Engine **engine,
+Common::Error CryOmni3DMetaEngine::createInstance(OSystem *syst, Engine **engine,
 		const ADGameDescription *desc) const {
 	const CryOmni3DGameDescription *gd = (const CryOmni3DGameDescription *)desc;
 
-	if (gd) {
-		switch (gd->gameType) {
-		case GType_VERSAILLES:
+	switch (gd->gameType) {
+	case GType_VERSAILLES:
 #ifdef ENABLE_VERSAILLES
-			*engine = new Versailles::CryOmni3DEngine_Versailles(syst, gd);
-			break;
+		*engine = new Versailles::CryOmni3DEngine_Versailles(syst, gd);
+		return Common::kNoError;
 #else
-			warning("Versailles support not compiled in");
-			return false;
+		return Common::Error(Common::kUnsupportedGameidError, _s("Versailles 1685 support is not compiled in"));
 #endif
-		default:
-			error("Unknown Cryo Omni3D Engine");
-		}
+	default:
+		return Common::kUnsupportedGameidError;
 	}
-
-	return (gd != 0);
 }
 
 } // End of namespace CryOmni3D
diff --git a/engines/director/metaengine.cpp b/engines/director/metaengine.cpp
index 9f545fcec9..7725dfca22 100644
--- a/engines/director/metaengine.cpp
+++ b/engines/director/metaengine.cpp
@@ -92,16 +92,12 @@ public:
 		return "director";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 };
 
-bool DirectorMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Director::DirectorGameDescription *gd = (const Director::DirectorGameDescription *)desc;
-
-	if (gd)
-		*engine = new Director::DirectorEngine(syst, gd);
-
-	return (gd != 0);
+Common::Error DirectorMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Director::DirectorEngine(syst, (const Director::DirectorGameDescription *)desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(DIRECTOR)
diff --git a/engines/dm/metaengine.cpp b/engines/dm/metaengine.cpp
index 25f585c2d3..891f1bdf8d 100644
--- a/engines/dm/metaengine.cpp
+++ b/engines/dm/metaengine.cpp
@@ -42,10 +42,9 @@ public:
 		return "dm";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
-		if (desc)
-			*engine = new DM::DMEngine(syst, (const DMADGameDescription*)desc);
-		return desc != nullptr;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
+		*engine = new DM::DMEngine(syst, (const DMADGameDescription*)desc);
+		return Common::kNoError;
 	}
 
 	bool hasFeature(MetaEngineFeature f) const override {
diff --git a/engines/draci/metaengine.cpp b/engines/draci/metaengine.cpp
index f211037d58..fa40d4f817 100644
--- a/engines/draci/metaengine.cpp
+++ b/engines/draci/metaengine.cpp
@@ -39,7 +39,7 @@ public:
 	SaveStateList listSaves(const char *target) const override;
 	void removeSaveState(const char *target, int slot) const override;
 	SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 };
 
 bool DraciMetaEngine::hasFeature(MetaEngineFeature f) const {
@@ -120,11 +120,9 @@ SaveStateDescriptor DraciMetaEngine::querySaveMetaInfos(const char *target, int
 	return SaveStateDescriptor();
 }
 
-bool DraciMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new Draci::DraciEngine(syst, desc);
-	}
-	return desc != 0;
+Common::Error DraciMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Draci::DraciEngine(syst, desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(DRACI)
diff --git a/engines/dragons/metaengine.cpp b/engines/dragons/metaengine.cpp
index dcf80c53ad..0ee2ca9016 100644
--- a/engines/dragons/metaengine.cpp
+++ b/engines/dragons/metaengine.cpp
@@ -38,7 +38,7 @@ public:
 	}
 
 	virtual bool hasFeature(MetaEngineFeature f) const override;
-	virtual bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	virtual Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	virtual int getMaximumSaveSlot() const override;
 	virtual SaveStateList listSaves(const char *target) const override;
 	SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const override;
@@ -113,23 +113,21 @@ SaveStateDescriptor DragonsMetaEngine::querySaveMetaInfos(const char *target, in
 	return SaveStateDescriptor();
 }
 
-bool DragonsMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error DragonsMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const Dragons::DragonsGameDescription *gd = (const Dragons::DragonsGameDescription *)desc;
-	if (gd) {
-		switch (gd->gameId) {
-		case Dragons::kGameIdDragons:
-			*engine = new Dragons::DragonsEngine(syst, desc);
-			break;
-		case Dragons::kGameIdDragonsBadExtraction:
-			GUIErrorMessageWithURL(_("Error: It appears that the game data files were extracted incorrectly.\n\nYou should only extract STR and XA files using the special method. The rest should be copied normally from your game CD.\n\n See https://wiki.scummvm.org/index.php?title=Datafiles#Blazing_Dragons"),
-								   "https://wiki.scummvm.org/index.php?title=Datafiles#Blazing_Dragons");
-			break;
-		default:
-			error("Unknown game id");
-			break;
-		}
+
+	switch (gd->gameId) {
+	case Dragons::kGameIdDragons:
+		*engine = new Dragons::DragonsEngine(syst, desc);
+		break;
+	case Dragons::kGameIdDragonsBadExtraction:
+		GUIErrorMessageWithURL(_("Error: It appears that the game data files were extracted incorrectly.\n\nYou should only extract STR and XA files using the special method. The rest should be copied normally from your game CD.\n\n See https://wiki.scummvm.org/index.php?title=Datafiles#Blazing_Dragons"),
+		                       "https://wiki.scummvm.org/index.php?title=Datafiles#Blazing_Dragons");
+		break;
+	default:
+		return Common::kUnsupportedGameidError;
 	}
-	return desc != 0;
+	return Common::kNoError;
 }
 
 Common::KeymapArray DragonsMetaEngine::initKeymaps(const char *target) const {
diff --git a/engines/drascula/metaengine.cpp b/engines/drascula/metaengine.cpp
index 1495ae7176..4ae15bb914 100644
--- a/engines/drascula/metaengine.cpp
+++ b/engines/drascula/metaengine.cpp
@@ -64,7 +64,7 @@ public:
 		return "drascula";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 
     SaveStateList listSaves(const char *target) const override;
@@ -157,12 +157,9 @@ void DrasculaMetaEngine::removeSaveState(const char *target, int slot) const {
 	g_system->getSavefileManager()->removeSavefile(fileName);
 }
 
-bool DrasculaMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Drascula::DrasculaGameDescription *gd = (const Drascula::DrasculaGameDescription *)desc;
-	if (gd) {
-		*engine = new Drascula::DrasculaEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error DrasculaMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Drascula::DrasculaEngine(syst, (const Drascula::DrasculaGameDescription *)desc);
+	return Common::kNoError;
 }
 
 } // End of namespace Drascula
diff --git a/engines/dreamweb/metaengine.cpp b/engines/dreamweb/metaengine.cpp
index 576d34378f..73248b6416 100644
--- a/engines/dreamweb/metaengine.cpp
+++ b/engines/dreamweb/metaengine.cpp
@@ -35,7 +35,7 @@ public:
 		return "dreamweb";
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	bool hasFeature(MetaEngineFeature f) const override;
 
@@ -71,12 +71,9 @@ bool DreamWeb::DreamWebEngine::hasFeature(EngineFeature f) const {
 	}
 }
 
-bool DreamWebMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const DreamWeb::DreamWebGameDescription *gd = (const DreamWeb::DreamWebGameDescription *)desc;
-	if (gd) {
-		*engine = new DreamWeb::DreamWebEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error DreamWebMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new DreamWeb::DreamWebEngine(syst, (const DreamWeb::DreamWebGameDescription *)desc);
+	return Common::kNoError;
 }
 
 SaveStateList DreamWebMetaEngine::listSaves(const char *target) const {
diff --git a/engines/gnap/metaengine.cpp b/engines/gnap/metaengine.cpp
index f12eda0652..de9ba01f64 100644
--- a/engines/gnap/metaengine.cpp
+++ b/engines/gnap/metaengine.cpp
@@ -36,7 +36,7 @@ public:
 	}
 
 	bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	int getMaximumSaveSlot() const override;
 	SaveStateList listSaves(const char *target) const override;
@@ -144,11 +144,9 @@ SaveStateDescriptor GnapMetaEngine::querySaveMetaInfos(const char *target, int s
 	return SaveStateDescriptor();
 }
 
-bool GnapMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new Gnap::GnapEngine(syst, desc);
-	}
-	return desc != 0;
+Common::Error GnapMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Gnap::GnapEngine(syst, desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(GNAP)
diff --git a/engines/gob/metaengine.cpp b/engines/gob/metaengine.cpp
index a4f24a091d..e257b1b7ec 100644
--- a/engines/gob/metaengine.cpp
+++ b/engines/gob/metaengine.cpp
@@ -35,8 +35,7 @@ public:
 
     bool hasFeature(MetaEngineFeature f) const override;
 
-	Common::Error createInstance(OSystem *syst, Engine **engine) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 };
 
 bool GobMetaEngine::hasFeature(MetaEngineFeature f) const {
@@ -48,17 +47,11 @@ bool Gob::GobEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsReturnToLauncher);
 }
 
-Common::Error GobMetaEngine::createInstance(OSystem *syst, Engine **engine) const {
-	return AdvancedMetaEngine::createInstance(syst, engine);
-}
-
-bool GobMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error GobMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const Gob::GOBGameDescription *gd = (const Gob::GOBGameDescription *)desc;
-	if (gd) {
-		*engine = new Gob::GobEngine(syst);
-		((Gob::GobEngine *)*engine)->initGame(gd);
-	}
-	return gd != 0;
+	*engine = new Gob::GobEngine(syst);
+	((Gob::GobEngine *)*engine)->initGame(gd);
+	return Common::kNoError;
 }
 
 
diff --git a/engines/griffon/metaengine.cpp b/engines/griffon/metaengine.cpp
index 86db14f6dd..b7f00eec14 100644
--- a/engines/griffon/metaengine.cpp
+++ b/engines/griffon/metaengine.cpp
@@ -41,7 +41,7 @@ public:
 		return ConfMan.getInt("autosave_period") ? 4 : 3;
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	virtual int getAutosaveSlot() const override {
 		return 4;
@@ -69,11 +69,9 @@ bool Griffon::GriffonEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool GriffonMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc)
-		*engine = new Griffon::GriffonEngine(syst);
-
-	return desc != nullptr;
+Common::Error GriffonMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Griffon::GriffonEngine(syst);
+	return Common::kNoError;
 }
 
 Common::KeymapArray GriffonMetaEngine::initKeymaps(const char *target) const {
diff --git a/engines/grim/POTFILES b/engines/grim/POTFILES
index ccb3ad89fb..071b0c6191 100644
--- a/engines/grim/POTFILES
+++ b/engines/grim/POTFILES
@@ -2,5 +2,6 @@ engines/grim/detection.cpp
 engines/grim/grim.cpp
 engines/grim/md5check.cpp
 engines/grim/md5checkdialog.cpp
+engines/grim/metaengine.cpp
 engines/grim/resource.cpp
 engines/grim/emi/sound/emisound.cpp
diff --git a/engines/grim/metaengine.cpp b/engines/grim/metaengine.cpp
index b6219538ef..7d16fcb65b 100644
--- a/engines/grim/metaengine.cpp
+++ b/engines/grim/metaengine.cpp
@@ -27,6 +27,7 @@
 
 #include "common/system.h"
 #include "common/savefile.h"
+#include "common/translation.h"
 #include "common/config-manager.h"
 
 namespace Grim {
@@ -42,7 +43,7 @@ public:
 		return AdvancedMetaEngine::createInstance(syst, engine);
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	bool hasFeature(MetaEngineFeature f) const override;
 
@@ -52,22 +53,20 @@ public:
 
 };
 
-bool GrimMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error GrimMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const GrimGameDescription *gd = (const GrimGameDescription *)desc;
 
-	if (gd) {
-		if (gd->gameType == GType_MONKEY4) {
+	if (gd->gameType == GType_MONKEY4) {
 #ifdef ENABLE_MONKEY4
-			*engine = new EMIEngine(syst, gd->desc.flags, gd->gameType, gd->desc.platform, gd->desc.language);
+		*engine = new EMIEngine(syst, gd->desc.flags, gd->gameType, gd->desc.platform, gd->desc.language);
 #else
-			return false;
+		return Common::Error(Common::kUnsupportedGameidError, _s("Escape from Monkey Island support is not compiled in"));
 #endif
-		} else {
-			*engine = new GrimEngine(syst, gd->desc.flags, gd->gameType, gd->desc.platform, gd->desc.language);
-		}
+	} else {
+		*engine = new GrimEngine(syst, gd->desc.flags, gd->gameType, gd->desc.platform, gd->desc.language);
 	}
 
-	return gd != nullptr;
+	return Common::kNoError;
 }
 
 bool GrimMetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/groovie/metaengine.cpp b/engines/groovie/metaengine.cpp
index 6f8a240272..25b483867f 100644
--- a/engines/groovie/metaengine.cpp
+++ b/engines/groovie/metaengine.cpp
@@ -37,7 +37,7 @@ public:
 		return "groovie";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 
 	SaveStateList listSaves(const char *target) const override;
@@ -46,18 +46,14 @@ public:
 	SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const override;
 };
 
-bool GroovieMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const {
-	if (gd) {
+Common::Error GroovieMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const {
 #ifndef ENABLE_GROOVIE2
-		if (((const GroovieGameDescription *)gd)->version == kGroovieV2) {
-			Engine::errorUnsupportedGame(_("GroovieV2 support is not compiled in"));
-			return false;
-		}
+	if (((const GroovieGameDescription *)gd)->version == kGroovieV2)
+		return Common::Error(Common::kUnsupportedGameidError, _s("GroovieV2 support is not compiled in"));
 #endif
 
-		*engine = new GroovieEngine(syst, (const GroovieGameDescription *)gd);
-	}
-	return gd != 0;
+	*engine = new GroovieEngine(syst, (const GroovieGameDescription *)gd);
+	return Common::kNoError;
 }
 
 bool GroovieMetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/hadesch/metaengine.cpp b/engines/hadesch/metaengine.cpp
index 1c7a609b12..bddd93e1cb 100644
--- a/engines/hadesch/metaengine.cpp
+++ b/engines/hadesch/metaengine.cpp
@@ -41,11 +41,9 @@ public:
 			(f == kSavesUseExtendedFormat);
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
-		if (desc)
-			*engine = new Hadesch::HadeschEngine(syst, desc);
-		
-		return desc != 0;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
+		*engine = new Hadesch::HadeschEngine(syst, desc);
+		return Common::kNoError;
 	}
 
 	const char *getName() const override {
diff --git a/engines/hdb/metaengine.cpp b/engines/hdb/metaengine.cpp
index cc04dfae5e..b50513a95b 100644
--- a/engines/hdb/metaengine.cpp
+++ b/engines/hdb/metaengine.cpp
@@ -76,7 +76,7 @@ public:
 	SaveStateList listSaves(const char *target) const override;
 	SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const override;
 	Common::KeymapArray initKeymaps(const char *target) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 };
 
 bool HDBMetaEngine::hasFeature(MetaEngineFeature f) const {
@@ -260,12 +260,9 @@ Common::KeymapArray HDBMetaEngine::initKeymaps(const char *target) const {
 	return Keymap::arrayOf(engineKeyMap);
 }
 
-bool HDBMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new HDB::HDBGame(syst, desc);
-	}
-
-	return desc != nullptr;
+Common::Error HDBMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new HDB::HDBGame(syst, desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(HDB)
diff --git a/engines/hopkins/metaengine.cpp b/engines/hopkins/metaengine.cpp
index d3f9d8a50d..b48748acdd 100644
--- a/engines/hopkins/metaengine.cpp
+++ b/engines/hopkins/metaengine.cpp
@@ -65,7 +65,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -90,12 +90,9 @@ bool Hopkins::HopkinsEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool HopkinsMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Hopkins::HopkinsGameDescription *gd = (const Hopkins::HopkinsGameDescription *)desc;
-	if (gd) {
-		*engine = new Hopkins::HopkinsEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error HopkinsMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Hopkins::HopkinsEngine(syst, (const Hopkins::HopkinsGameDescription *)desc);
+	return Common::kNoError;
 }
 
 SaveStateList HopkinsMetaEngine::listSaves(const char *target) const {
diff --git a/engines/hugo/metaengine.cpp b/engines/hugo/metaengine.cpp
index 0169549d44..731bc5e479 100644
--- a/engines/hugo/metaengine.cpp
+++ b/engines/hugo/metaengine.cpp
@@ -46,7 +46,7 @@ public:
 		return "hugo";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 
 	int getMaximumSaveSlot() const override;
@@ -56,12 +56,10 @@ public:
 
 };
 
-bool HugoMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const {
-	if (gd) {
-		*engine = new HugoEngine(syst, (const HugoGameDescription *)gd);
-		((HugoEngine *)*engine)->initGame((const HugoGameDescription *)gd);
-	}
-	return gd != 0;
+Common::Error HugoMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const {
+	*engine = new HugoEngine(syst, (const HugoGameDescription *)gd);
+	((HugoEngine *)*engine)->initGame((const HugoGameDescription *)gd);
+	return Common::kNoError;
 }
 
 bool HugoMetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/icb/metaengine.cpp b/engines/icb/metaengine.cpp
index eb9050d868..c54140d6cf 100644
--- a/engines/icb/metaengine.cpp
+++ b/engines/icb/metaengine.cpp
@@ -34,14 +34,12 @@ public:
 	}
 	virtual bool hasFeature(MetaEngineFeature f) const override { return false; }
 
-	virtual bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	virtual Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 };
 
-bool IcbMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc)
-		*engine = new IcbEngine(syst, desc);
-
-	return desc != nullptr;
+Common::Error IcbMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new IcbEngine(syst, desc);
+	return Common::kNoError;
 }
 
 } // End of namespace ICB
diff --git a/engines/illusions/metaengine.cpp b/engines/illusions/metaengine.cpp
index ae54d008ed..12456248ce 100644
--- a/engines/illusions/metaengine.cpp
+++ b/engines/illusions/metaengine.cpp
@@ -52,7 +52,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	int getMaximumSaveSlot() const override;
 	SaveStateList listSaves(const char *target) const override;
@@ -127,22 +127,19 @@ SaveStateDescriptor IllusionsMetaEngine::querySaveMetaInfos(const char *target,
 	return SaveStateDescriptor();
 }
 
-bool IllusionsMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error IllusionsMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const Illusions::IllusionsGameDescription *gd = (const Illusions::IllusionsGameDescription *)desc;
-	if (gd) {
-		switch (gd->gameId) {
-		case Illusions::kGameIdBBDOU:
-			*engine = new Illusions::IllusionsEngine_BBDOU(syst, gd);
-			break;
-		case Illusions::kGameIdDuckman:
-			*engine = new Illusions::IllusionsEngine_Duckman(syst, gd);
-			break;
-		default:
-			error("Unknown game id");
-			break;
-		}
+	switch (gd->gameId) {
+	case Illusions::kGameIdBBDOU:
+		*engine = new Illusions::IllusionsEngine_BBDOU(syst, gd);
+		break;
+	case Illusions::kGameIdDuckman:
+		*engine = new Illusions::IllusionsEngine_Duckman(syst, gd);
+		break;
+	default:
+		return Common::kUnsupportedGameidError;
 	}
-	return desc != 0;
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(ILLUSIONS)
diff --git a/engines/kingdom/metaengine.cpp b/engines/kingdom/metaengine.cpp
index 4b130f387a..a7f55937ea 100644
--- a/engines/kingdom/metaengine.cpp
+++ b/engines/kingdom/metaengine.cpp
@@ -45,7 +45,7 @@ public:
 	}
 
 	virtual bool hasFeature(MetaEngineFeature f) const override;
-	virtual bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	virtual Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	virtual int getMaximumSaveSlot() const override;
 	virtual SaveStateList listSaves(const char *target) const override;
@@ -63,11 +63,9 @@ bool KingdomMetaEngine::hasFeature(MetaEngineFeature f) const {
 	    (f == kSavesSupportCreationDate);
 }
 
-bool KingdomMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc)
-		*engine = new Kingdom::KingdomGame(syst, desc);
-
-	return desc != nullptr;
+Common::Error KingdomMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Kingdom::KingdomGame(syst, desc);
+	return Common::kNoError;
 }
 
 int KingdomMetaEngine::getMaximumSaveSlot() const {
diff --git a/engines/kyra/metaengine.cpp b/engines/kyra/metaengine.cpp
index d719f3d01e..7f4f4aad8b 100644
--- a/engines/kyra/metaengine.cpp
+++ b/engines/kyra/metaengine.cpp
@@ -45,7 +45,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -74,9 +74,8 @@ bool Kyra::KyraEngine_v1::hasFeature(EngineFeature f) const {
 	    (f == kSupportsSubtitleOptions);
 }
 
-bool KyraMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error KyraMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const KYRAGameDescription *gd = (const KYRAGameDescription *)desc;
-	bool res = true;
 
 	Kyra::GameFlags flags = gd->flags;
 
@@ -109,14 +108,14 @@ bool KyraMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGame
 	case Kyra::GI_KYRA3:
 		*engine = new Kyra::KyraEngine_MR(syst, flags);
 		break;
-	case Kyra::GI_LOL:
 #ifdef ENABLE_LOL
+	case Kyra::GI_LOL:
 		*engine = new Kyra::LoLEngine(syst, flags);
+		break;
 #else
-		Engine::errorUnsupportedGame(_("Lands of Lore support is not compiled in"));
-		res = false;
+	case Kyra::GI_LOL:
+		return Common::Error(Common::kUnsupportedGameidError, _s("Lands of Lore support is not compiled in"));
 #endif // ENABLE_LOL
-		break;
 #ifdef ENABLE_EOB
 	case Kyra::GI_EOB1:
 		*engine = new Kyra::EoBEngine(syst, flags);
@@ -124,26 +123,20 @@ bool KyraMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGame
 	case Kyra::GI_EOB2:
 		 if (Common::parseRenderMode(ConfMan.get("render_mode")) == Common::kRenderEGA)
 			 flags.useHiRes = true;
-		 if (platform == Common::kPlatformFMTowns && !flags.useHiColorMode) {
-			 Engine::errorUnsupportedGame(_("EOB II FM-TOWNS requires support of 16bit color modes which has not been activated in your ScummVM build"));
-			 res = false;
-			 break;
-		 }
+		 if (platform == Common::kPlatformFMTowns && !flags.useHiColorMode)
+			 return Common::Error(Common::kUnsupportedColorMode, _s("EOB II FM-TOWNS requires support of 16bit color modes which has not been activated in your ScummVM build"));
 		*engine = new Kyra::DarkMoonEngine(syst, flags);
 		break;
 #else
 	case Kyra::GI_EOB1:
 	case Kyra::GI_EOB2:
-		Engine::errorUnsupportedGame(_("Eye of Beholder support is not compiled in"));
-		res = false;
-		break;
+		return Common::Error(Common::kUnsupportedGameidError, _s("Eye of Beholder support is not compiled in"));
 #endif // ENABLE_EOB
 	default:
-		res = false;
-		warning("Kyra engine: unknown gameID");
+		return Common::kUnsupportedGameidError;
 	}
 
-	return res;
+	return Common::kNoError;
 }
 
 SaveStateList KyraMetaEngine::listSaves(const char *target) const {
diff --git a/engines/lab/metaengine.cpp b/engines/lab/metaengine.cpp
index bf69e15149..edc35a7042 100644
--- a/engines/lab/metaengine.cpp
+++ b/engines/lab/metaengine.cpp
@@ -49,10 +49,9 @@ public:
 		return "lab";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
-		// Instantiate Engine even if the game data is not found.
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
 		*engine = new Lab::LabEngine(syst, desc);
-		return true;
+		return Common::kNoError;
 	}
 
 	bool hasFeature(MetaEngineFeature f) const override;
diff --git a/engines/lastexpress/metaengine.cpp b/engines/lastexpress/metaengine.cpp
index 54bef00bcc..b9fc0a9508 100644
--- a/engines/lastexpress/metaengine.cpp
+++ b/engines/lastexpress/metaengine.cpp
@@ -32,14 +32,12 @@ public:
 	}
 
 protected:
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
 };
 
-bool LastExpressMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const {
-	if (gd) {
-		*engine = new LastExpressEngine(syst, (const ADGameDescription *)gd);
-	}
-	return gd != 0;
+Common::Error LastExpressMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const {
+	*engine = new LastExpressEngine(syst, (const ADGameDescription *)gd);
+	return Common::kNoError;
 }
 
 bool LastExpressEngine::isDemo() const {
diff --git a/engines/lilliput/metaengine.cpp b/engines/lilliput/metaengine.cpp
index 3a837940e2..a33b44833b 100644
--- a/engines/lilliput/metaengine.cpp
+++ b/engines/lilliput/metaengine.cpp
@@ -50,7 +50,7 @@ public:
 		return "lilliput";
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 
 	int getMaximumSaveSlot() const override;
@@ -59,12 +59,10 @@ public:
 	void removeSaveState(const char *target, int slot) const override;
 };
 
-bool LilliputMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const {
-	if (gd) {
-		*engine = new LilliputEngine(syst, (const LilliputGameDescription *)gd);
-		((LilliputEngine *)*engine)->initGame((const LilliputGameDescription *)gd);
-	}
-	return gd != 0;
+Common::Error LilliputMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const {
+	*engine = new LilliputEngine(syst, (const LilliputGameDescription *)gd);
+	((LilliputEngine *)*engine)->initGame((const LilliputGameDescription *)gd);
+	return Common::kNoError;
 }
 
 bool LilliputMetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/lure/metaengine.cpp b/engines/lure/metaengine.cpp
index 7bac80b7c9..aa114f3c97 100644
--- a/engines/lure/metaengine.cpp
+++ b/engines/lure/metaengine.cpp
@@ -57,7 +57,7 @@ public:
 	}
 
 	bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -78,12 +78,9 @@ bool Lure::LureEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool LureMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Lure::LureGameDescription *gd = (const Lure::LureGameDescription *)desc;
-	if (gd) {
-		*engine = new Lure::LureEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error LureMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Lure::LureEngine(syst, (const Lure::LureGameDescription *)desc);
+	return Common::kNoError;
 }
 
 SaveStateList LureMetaEngine::listSaves(const char *target) const {
diff --git a/engines/macventure/metaengine.cpp b/engines/macventure/metaengine.cpp
index 5edf092636..42bed3b36b 100644
--- a/engines/macventure/metaengine.cpp
+++ b/engines/macventure/metaengine.cpp
@@ -47,7 +47,7 @@ public:
 	}
 
 protected:
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -113,11 +113,9 @@ SaveStateList MacVentureMetaEngine::listSaves(const char *target) const {
 
 int MacVentureMetaEngine::getMaximumSaveSlot() const { return 999; }
 
-bool MacVentureMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *game) const {
-	if (game) {
-		*engine = new MacVenture::MacVentureEngine(syst, game);
-	}
-	return game != 0;
+Common::Error MacVentureMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *game) const {
+	*engine = new MacVenture::MacVentureEngine(syst, game);
+	return Common::kNoError;
 }
 
 void MacVentureMetaEngine::removeSaveState(const char *target, int slot) const {
diff --git a/engines/made/metaengine.cpp b/engines/made/metaengine.cpp
index e3d98df657..cb37dca717 100644
--- a/engines/made/metaengine.cpp
+++ b/engines/made/metaengine.cpp
@@ -52,7 +52,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 };
 
 bool MadeMetaEngine::hasFeature(MetaEngineFeature f) const {
@@ -65,12 +65,9 @@ bool Made::MadeEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsReturnToLauncher);
 }
 
-bool MadeMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Made::MadeGameDescription *gd = (const Made::MadeGameDescription *)desc;
-	if (gd) {
-		*engine = new Made::MadeEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error MadeMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Made::MadeEngine(syst, (const Made::MadeGameDescription *)desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(MADE)
diff --git a/engines/mads/metaengine.cpp b/engines/mads/metaengine.cpp
index aef4e838c5..9170c6a190 100644
--- a/engines/mads/metaengine.cpp
+++ b/engines/mads/metaengine.cpp
@@ -69,7 +69,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -94,12 +94,9 @@ bool MADS::MADSEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool MADSMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const MADS::MADSGameDescription *gd = (const MADS::MADSGameDescription *)desc;
-	if (gd) {
-		*engine = new MADS::MADSEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error MADSMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new MADS::MADSEngine(syst, (const MADS::MADSGameDescription *)desc);
+	return Common::kNoError;
 }
 
 SaveStateList MADSMetaEngine::listSaves(const char *target) const {
diff --git a/engines/mohawk/POTFILES b/engines/mohawk/POTFILES
index 97aa6ca256..a9216b14ef 100644
--- a/engines/mohawk/POTFILES
+++ b/engines/mohawk/POTFILES
@@ -1,5 +1,6 @@
 engines/mohawk/detection.cpp
 engines/mohawk/dialogs.cpp
+engines/mohawk/metaengine.cpp
 engines/mohawk/mohawk.cpp
 engines/mohawk/metaengine.cpp
 engines/mohawk/myst.cpp
diff --git a/engines/mohawk/metaengine.cpp b/engines/mohawk/metaengine.cpp
index 9f5684f42a..726fedcae4 100644
--- a/engines/mohawk/metaengine.cpp
+++ b/engines/mohawk/metaengine.cpp
@@ -127,7 +127,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	SaveStateList listSavesForPrefix(const char *prefix, const char *extension) const;
@@ -259,55 +259,48 @@ Common::KeymapArray MohawkMetaEngine::initKeymaps(const char *target) const {
 	return AdvancedMetaEngine::initKeymaps(target);
 }
 
-bool MohawkMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error MohawkMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const Mohawk::MohawkGameDescription *gd = (const Mohawk::MohawkGameDescription *)desc;
 
-	if (gd) {
-		switch (gd->gameType) {
-		case Mohawk::GType_MYST:
-		case Mohawk::GType_MAKINGOF:
+	switch (gd->gameType) {
+	case Mohawk::GType_MYST:
+	case Mohawk::GType_MAKINGOF:
 #ifdef ENABLE_MYST
 #ifndef ENABLE_MYSTME
-			if (gd->features & Mohawk::GF_ME) {
-				Engine::errorUnsupportedGame(_("Myst ME support not compiled in"));
-				return false;
-			}
+		if (gd->features & Mohawk::GF_ME)
+			return Common::Error(Common::kUnsupportedGameidError, _s("Myst ME support not compiled in"));
 #endif
-			*engine = new Mohawk::MohawkEngine_Myst(syst, gd);
-			break;
+		*engine = new Mohawk::MohawkEngine_Myst(syst, gd);
+		break;
 #else
-			Engine::errorUnsupportedGame(_("Myst support not compiled in"));
-			return false;
+		return Common::Error(Common::kUnsupportedGameidError, _s("Myst support not compiled in"));
 #endif
-		case Mohawk::GType_RIVEN:
+	case Mohawk::GType_RIVEN:
 #ifdef ENABLE_RIVEN
-			*engine = new Mohawk::MohawkEngine_Riven(syst, gd);
-			break;
+		*engine = new Mohawk::MohawkEngine_Riven(syst, gd);
+		break;
 #else
-			Engine::errorUnsupportedGame(_("Riven support not compiled in"));
-			return false;
+		return Common::Error(Common::kUnsupportedGameidError, _s("Riven support not compiled in"));
 #endif
-		case Mohawk::GType_LIVINGBOOKSV1:
-		case Mohawk::GType_LIVINGBOOKSV2:
-		case Mohawk::GType_LIVINGBOOKSV3:
-		case Mohawk::GType_LIVINGBOOKSV4:
-		case Mohawk::GType_LIVINGBOOKSV5:
-			*engine = new Mohawk::MohawkEngine_LivingBooks(syst, gd);
-			break;
-		case Mohawk::GType_CSTIME:
+	case Mohawk::GType_LIVINGBOOKSV1:
+	case Mohawk::GType_LIVINGBOOKSV2:
+	case Mohawk::GType_LIVINGBOOKSV3:
+	case Mohawk::GType_LIVINGBOOKSV4:
+	case Mohawk::GType_LIVINGBOOKSV5:
+		*engine = new Mohawk::MohawkEngine_LivingBooks(syst, gd);
+		break;
+	case Mohawk::GType_CSTIME:
 #ifdef ENABLE_CSTIME
-			*engine = new Mohawk::MohawkEngine_CSTime(syst, gd);
-			break;
+		*engine = new Mohawk::MohawkEngine_CSTime(syst, gd);
+		break;
 #else
-			Engine::errorUnsupportedGame(_("CSTime support not compiled in"));
-			return false;
+		return Common::Error(Common::kUnsupportedGameidError, _s("CSTime support not compiled in"));
 #endif
-		default:
-			error("Unknown Mohawk Engine");
-		}
+	default:
+		return Common::kUnsupportedGameidError;
 	}
 
-	return (gd != nullptr);
+	return Common::kNoError;
 }
 
 GUI::OptionsContainerWidget *MohawkMetaEngine::buildEngineOptionsWidgetDynamic(GUI::GuiObject *boss, const Common::String &name, const Common::String &target) const {
diff --git a/engines/mortevielle/metaengine.cpp b/engines/mortevielle/metaengine.cpp
index 0ce49d3dcd..f084fb2f45 100644
--- a/engines/mortevielle/metaengine.cpp
+++ b/engines/mortevielle/metaengine.cpp
@@ -45,7 +45,7 @@ public:
 		return "mortevielle";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 
 	int getMaximumSaveSlot() const override;
@@ -53,11 +53,9 @@ public:
 	SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const override;
 };
 
-bool MortevielleMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new Mortevielle::MortevielleEngine(syst, (const Mortevielle::MortevielleGameDescription *)desc);
-	}
-	return desc != 0;
+Common::Error MortevielleMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Mortevielle::MortevielleEngine(syst, (const Mortevielle::MortevielleGameDescription *)desc);
+	return Common::kNoError;
 }
 
 bool MortevielleMetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/mutationofjb/metaengine.cpp b/engines/mutationofjb/metaengine.cpp
index 9f23d23755..0e2e41892b 100644
--- a/engines/mutationofjb/metaengine.cpp
+++ b/engines/mutationofjb/metaengine.cpp
@@ -35,11 +35,9 @@ public:
 		return "mutationofjb";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
-		if (desc) {
-			*engine = new MutationOfJB::MutationOfJBEngine(syst, desc);
-		}
-		return desc != nullptr;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
+		*engine = new MutationOfJB::MutationOfJBEngine(syst, desc);
+		return Common::kNoError;
 	}
 
 	bool hasFeature(MetaEngineFeature f) const override {
diff --git a/engines/myst3/metaengine.cpp b/engines/myst3/metaengine.cpp
index 5d6904eb68..80dea6589b 100644
--- a/engines/myst3/metaengine.cpp
+++ b/engines/myst3/metaengine.cpp
@@ -131,15 +131,12 @@ public:
 		return 999;
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 };
 
-bool Myst3MetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Myst3GameDescription *gd = (const Myst3GameDescription *)desc;
-	if (gd) {
-		*engine = new Myst3Engine(syst, gd);
-	}
-	return gd != 0;
+Common::Error Myst3MetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Myst3Engine(syst, (const Myst3GameDescription *)desc);
+	return Common::kNoError;
 }
 
 Common::Platform Myst3Engine::getPlatform() const {
diff --git a/engines/neverhood/metaengine.cpp b/engines/neverhood/metaengine.cpp
index ffdb77914e..7c8b329123 100644
--- a/engines/neverhood/metaengine.cpp
+++ b/engines/neverhood/metaengine.cpp
@@ -63,7 +63,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -90,11 +90,9 @@ bool Neverhood::NeverhoodEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool NeverhoodMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new Neverhood::NeverhoodEngine(syst, desc);
-	}
-	return desc != 0;
+Common::Error NeverhoodMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Neverhood::NeverhoodEngine(syst, desc);
+	return Common::kNoError;
 }
 
 SaveStateList NeverhoodMetaEngine::listSaves(const char *target) const {
diff --git a/engines/ngi/metaengine.cpp b/engines/ngi/metaengine.cpp
index 129a77f915..46368f7a4f 100644
--- a/engines/ngi/metaengine.cpp
+++ b/engines/ngi/metaengine.cpp
@@ -68,7 +68,7 @@ public:
 	void removeSaveState(const char *target, int slot) const override;
 	SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const override;
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 };
 
 bool NGIMetaEngine::hasFeature(MetaEngineFeature f) const {
@@ -154,13 +154,9 @@ SaveStateDescriptor NGIMetaEngine::querySaveMetaInfos(const char *target, int sl
 	return SaveStateDescriptor();
 }
 
-bool NGIMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const NGI::NGIGameDescription *gd = (const NGI::NGIGameDescription *)desc;
-
-	if (gd) {
-		*engine = new NGI::NGIEngine(syst, gd);
-	}
-	return desc != 0;
+Common::Error NGIMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new NGI::NGIEngine(syst, (const NGI::NGIGameDescription *)desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(NGI)
diff --git a/engines/parallaction/metaengine.cpp b/engines/parallaction/metaengine.cpp
index 82231a74aa..085e7409b1 100644
--- a/engines/parallaction/metaengine.cpp
+++ b/engines/parallaction/metaengine.cpp
@@ -46,7 +46,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -64,9 +64,8 @@ bool Parallaction::Parallaction::hasFeature(EngineFeature f) const {
 		(f == kSupportsReturnToLauncher);
 }
 
-bool ParallactionMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error ParallactionMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const Parallaction::PARALLACTIONGameDescription *gd = (const Parallaction::PARALLACTIONGameDescription *)desc;
-	bool res = true;
 
 	switch (gd->gameType) {
 	case Parallaction::GType_Nippon:
@@ -76,11 +75,10 @@ bool ParallactionMetaEngine::createInstance(OSystem *syst, Engine **engine, cons
 		*engine = new Parallaction::Parallaction_br(syst, gd);
 		break;
 	default:
-		res = false;
-		error("Parallaction engine: unknown gameType");
+		return Common::kUnsupportedGameidError;
 	}
 
-	return res;
+	return Common::kNoError;
 }
 
 SaveStateList ParallactionMetaEngine::listSaves(const char *target) const {
diff --git a/engines/pegasus/metaengine.cpp b/engines/pegasus/metaengine.cpp
index 33f0896307..aefc3b74c5 100644
--- a/engines/pegasus/metaengine.cpp
+++ b/engines/pegasus/metaengine.cpp
@@ -68,7 +68,7 @@ public:
 	}
 
 	bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override { return 999; }
@@ -112,13 +112,9 @@ Common::KeymapArray PegasusMetaEngine::initKeymaps(const char *target) const {
 	return Pegasus::PegasusEngine::initKeymaps();
 }
 
-bool PegasusMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Pegasus::PegasusGameDescription *gd = (const Pegasus::PegasusGameDescription *)desc;
-
-	if (gd)
-		*engine = new Pegasus::PegasusEngine(syst, gd);
-
-	return (gd != 0);
+Common::Error PegasusMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Pegasus::PegasusEngine(syst, (const Pegasus::PegasusGameDescription *)desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(PEGASUS)
diff --git a/engines/petka/metaengine.cpp b/engines/petka/metaengine.cpp
index 1cc08b1d90..4a7b7be67a 100644
--- a/engines/petka/metaengine.cpp
+++ b/engines/petka/metaengine.cpp
@@ -38,7 +38,7 @@ public:
 	virtual SaveStateList listSaves(const char *target) const override;
 	virtual void removeSaveState(const char *target, int slot) const override;
 	virtual SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const override;
-	virtual bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	virtual Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 };
 
 bool PetkaMetaEngine::hasFeature(MetaEngineFeature f) const {
@@ -96,11 +96,9 @@ SaveStateDescriptor PetkaMetaEngine::querySaveMetaInfos(const char *target, int
 	return SaveStateDescriptor();
 }
 
-bool PetkaMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc)
-		*engine = new Petka::PetkaEngine(syst, desc);
-
-	return desc != 0;
+Common::Error PetkaMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Petka::PetkaEngine(syst, desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(PETKA)
diff --git a/engines/pink/metaengine.cpp b/engines/pink/metaengine.cpp
index 3ccc372348..c94b73506a 100644
--- a/engines/pink/metaengine.cpp
+++ b/engines/pink/metaengine.cpp
@@ -47,7 +47,7 @@ public:
 	void removeSaveState(const char *target, int slot) const override;
 	SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const override;
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 };
 
 bool PinkMetaEngine::hasFeature(MetaEngineFeature f) const {
@@ -105,11 +105,9 @@ SaveStateDescriptor PinkMetaEngine::querySaveMetaInfos(const char *target, int s
 	return SaveStateDescriptor();
 }
 
-bool PinkMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc)
-		*engine = new Pink::PinkEngine(syst, desc);
-
-	return desc != 0;
+Common::Error PinkMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Pink::PinkEngine(syst, desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(PINK)
diff --git a/engines/plumbers/metaengine.cpp b/engines/plumbers/metaengine.cpp
index fd775cc855..fb44da3d82 100644
--- a/engines/plumbers/metaengine.cpp
+++ b/engines/plumbers/metaengine.cpp
@@ -36,15 +36,13 @@ class PlumbersMetaEngine : public AdvancedMetaEngine {
 		return "plumbers";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 };
 
-bool PlumbersMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc)
-		*engine = new Plumbers::PlumbersGame(syst, desc);
-
-	return desc != nullptr;
+Common::Error PlumbersMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Plumbers::PlumbersGame(syst, desc);
+	return Common::kNoError;
 }
 
 bool PlumbersMetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/prince/metaengine.cpp b/engines/prince/metaengine.cpp
index 810dec7070..cb54f7ce21 100644
--- a/engines/prince/metaengine.cpp
+++ b/engines/prince/metaengine.cpp
@@ -50,7 +50,7 @@ public:
 		return "prince";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 
 	int getMaximumSaveSlot() const override { return 99; }
@@ -159,13 +159,9 @@ void PrinceMetaEngine::removeSaveState(const char *target, int slot) const {
 	g_system->getSavefileManager()->removeSavefile(fileName);
 }
 
-bool PrinceMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	using namespace Prince;
-	const PrinceGameDescription *gd = (const PrinceGameDescription *)desc;
-	if (gd) {
-		*engine = new PrinceEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error PrinceMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Prince::PrinceEngine(syst, (const Prince::PrinceGameDescription *)desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(PRINCE)
diff --git a/engines/queen/metaengine.cpp b/engines/queen/metaengine.cpp
index f1cdaded69..5529281adc 100644
--- a/engines/queen/metaengine.cpp
+++ b/engines/queen/metaengine.cpp
@@ -36,7 +36,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override { return 99; }
 	void removeSaveState(const char *target, int slot) const override;
@@ -86,13 +86,9 @@ void QueenMetaEngine::removeSaveState(const char *target, int slot) const {
 	g_system->getSavefileManager()->removeSavefile(filename);
 }
 
-bool QueenMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Queen::QueenGameDescription *gd = (const Queen::QueenGameDescription *)desc;
-
-	if (gd)
-		*engine = new Queen::QueenEngine(syst); //FIXME , gd);
-
-	return (gd != 0);
+Common::Error QueenMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Queen::QueenEngine(syst); //FIXME , (const Queen::QueenGameDescription *)desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(QUEEN)
diff --git a/engines/saga/metaengine.cpp b/engines/saga/metaengine.cpp
index 87428e20a7..cfe28f1b1a 100644
--- a/engines/saga/metaengine.cpp
+++ b/engines/saga/metaengine.cpp
@@ -78,10 +78,7 @@ public:
 
     bool hasFeature(MetaEngineFeature f) const override;
 
-	Common::Error createInstance(OSystem *syst, Engine **engine) const override {
-		return AdvancedMetaEngine::createInstance(syst, engine);
-	}
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -108,31 +105,27 @@ bool Saga::SagaEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool SagaMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error SagaMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const Saga::SAGAGameDescription *gd = (const Saga::SAGAGameDescription *)desc;
 
 	switch (gd->gameId) {
 	case Saga::GID_IHNM:
 #ifndef ENABLE_IHNM
-		Engine::errorUnsupportedGame(_("I Have No Mouth support not compiled in"));
-		return false;
+		return Common::Error(Common::kUnsupportedGameidError, _s("I Have No Mouth support not compiled in"));
 #endif
 		break;
 	case Saga::GID_DINO:
 	case Saga::GID_FTA2:
 #ifndef ENABLE_SAGA2
-		Engine::errorUnsupportedGame(_("SAGA2 support not compiled in"));
-		return false;
+		return Common::Error(Common::kUnsupportedGameidError, _s("SAGA2 support not compiled in"));
 #endif
 		break;
 	default:
 		break;
 	}
 
-	if (gd) {
-		*engine = new Saga::SagaEngine(syst, gd);
-	}
-	return gd != 0;
+	*engine = new Saga::SagaEngine(syst, gd);
+	return Common::kNoError;
 }
 
 SaveStateList SagaMetaEngine::listSaves(const char *target) const {
diff --git a/engines/sci/metaengine.cpp b/engines/sci/metaengine.cpp
index 3b4afe76a7..a9985414b7 100644
--- a/engines/sci/metaengine.cpp
+++ b/engines/sci/metaengine.cpp
@@ -303,7 +303,7 @@ public:
 		return "sci";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *gd) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 
 	SaveStateList listSaves(const char *target) const override;
@@ -316,7 +316,7 @@ public:
 	virtual ADDetectedGame fallbackDetectExtern(uint md5Bytes, const FileMap &allFiles, const Common::FSList &fslist) const override;
 };
 
-bool SciMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error SciMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const GameIdStrToEnum *g = s_gameIdStrToEnum;
 	for (; g->gameidStr; ++g) {
 		if (0 == strcmp(desc->gameId, g->gameidStr)) {
@@ -328,11 +328,11 @@ bool SciMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameD
 #endif
 
 			*engine = new SciEngine(syst, desc, g->gameidEnum);
-			return true;
+			return Common::kNoError;
 		}
 	}
 
-	return false;
+	return Common::kUnsupportedGameidError;
 }
 
 bool SciMetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/sherlock/metaengine.cpp b/engines/sherlock/metaengine.cpp
index 7838cc5a06..43d233b930 100644
--- a/engines/sherlock/metaengine.cpp
+++ b/engines/sherlock/metaengine.cpp
@@ -56,7 +56,7 @@ public:
     /**
 	 * Creates an instance of the game engine
 	 */
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	/**
 	 * Returns a list of features the game's MetaEngine support
@@ -84,22 +84,19 @@ public:
 	SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const override;
 };
 
-bool SherlockMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error SherlockMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const Sherlock::SherlockGameDescription *gd = (const Sherlock::SherlockGameDescription *)desc;
-	if (gd) {
-		switch (gd->gameID) {
-		case Sherlock::GType_SerratedScalpel:
-			*engine = new Sherlock::Scalpel::ScalpelEngine(syst, gd);
-			break;
-		case Sherlock::GType_RoseTattoo:
-			*engine = new Sherlock::Tattoo::TattooEngine(syst, gd);
-			break;
-		default:
-			error("Unknown game");
-			break;
-		}
+	switch (gd->gameID) {
+	case Sherlock::GType_SerratedScalpel:
+		*engine = new Sherlock::Scalpel::ScalpelEngine(syst, gd);
+		break;
+	case Sherlock::GType_RoseTattoo:
+		*engine = new Sherlock::Tattoo::TattooEngine(syst, gd);
+		break;
+	default:
+		return Common::kUnsupportedGameidError;
 	}
-	return gd != 0;
+	return Common::kNoError;
 }
 
 bool SherlockMetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/sludge/metaengine.cpp b/engines/sludge/metaengine.cpp
index 26f9295a53..ef9b740fd1 100644
--- a/engines/sludge/metaengine.cpp
+++ b/engines/sludge/metaengine.cpp
@@ -46,12 +46,9 @@ public:
 		return "sludge";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
-		const Sludge::SludgeGameDescription *gd = (const Sludge::SludgeGameDescription *)desc;
-			if (gd) {
-				*engine = new Sludge::SludgeEngine(syst, gd);
-			}
-			return gd != 0;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
+		*engine = new Sludge::SludgeEngine(syst, (const Sludge::SludgeGameDescription *)desc);
+		return Common::kNoError;
 	}
 };
 
diff --git a/engines/stark/metaengine.cpp b/engines/stark/metaengine.cpp
index da7e7e5778..def0324ead 100644
--- a/engines/stark/metaengine.cpp
+++ b/engines/stark/metaengine.cpp
@@ -114,11 +114,9 @@ public:
 		g_system->getSavefileManager()->removeSavefile(filename);
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
-		if (desc)
-			*engine = new StarkEngine(syst, desc);
-
-		return desc != nullptr;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
+		*engine = new StarkEngine(syst, desc);
+		return Common::kNoError;
 	}    
 };
 
diff --git a/engines/startrek/metaengine.cpp b/engines/startrek/metaengine.cpp
index 3775629358..1e2eef5a4c 100644
--- a/engines/startrek/metaengine.cpp
+++ b/engines/startrek/metaengine.cpp
@@ -61,7 +61,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -81,12 +81,9 @@ bool StarTrekMetaEngine::hasFeature(MetaEngineFeature f) const {
 	    (f == kSimpleSavesNames);
 }
 
-bool StarTrekMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const StarTrek::StarTrekGameDescription *gd = (const StarTrek::StarTrekGameDescription *)desc;
-
-	*engine = new StarTrek::StarTrekEngine(syst, gd);
-
-	return (gd != 0);
+Common::Error StarTrekMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new StarTrek::StarTrekEngine(syst, (const StarTrek::StarTrekGameDescription *)desc);
+	return Common::kNoError;
 }
 
 SaveStateList StarTrekMetaEngine::listSaves(const char *target) const {
diff --git a/engines/supernova/metaengine.cpp b/engines/supernova/metaengine.cpp
index ba63e096fe..810caa5818 100644
--- a/engines/supernova/metaengine.cpp
+++ b/engines/supernova/metaengine.cpp
@@ -37,7 +37,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	void removeSaveState(const char *target, int slot) const override;
@@ -62,12 +62,9 @@ bool SupernovaMetaEngine::hasFeature(MetaEngineFeature f) const {
 	}
 }
 
-bool SupernovaMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new Supernova::SupernovaEngine(syst);
-	}
-
-	return desc != nullptr;
+Common::Error SupernovaMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Supernova::SupernovaEngine(syst);
+	return Common::kNoError;
 }
 
 SaveStateList SupernovaMetaEngine::listSaves(const char *target) const {
diff --git a/engines/sword25/metaengine.cpp b/engines/sword25/metaengine.cpp
index 0c7fc563a8..7641240e0b 100644
--- a/engines/sword25/metaengine.cpp
+++ b/engines/sword25/metaengine.cpp
@@ -37,18 +37,16 @@ public:
 		return "sword25";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	bool hasFeature(MetaEngineFeature f) const override;
 
     int getMaximumSaveSlot() const override { return Sword25::PersistenceService::getSlotCount(); }
 	SaveStateList listSaves(const char *target) const override;
 };
 
-bool Sword25MetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new Sword25::Sword25Engine(syst, desc);
-	}
-	return desc != 0;
+Common::Error Sword25MetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Sword25::Sword25Engine(syst, desc);
+	return Common::kNoError;
 }
 
 bool Sword25MetaEngine::hasFeature(MetaEngineFeature f) const {
diff --git a/engines/teenagent/metaengine.cpp b/engines/teenagent/metaengine.cpp
index d6f3883943..692e6277b1 100644
--- a/engines/teenagent/metaengine.cpp
+++ b/engines/teenagent/metaengine.cpp
@@ -54,11 +54,9 @@ public:
 		}
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
-		if (desc) {
-			*engine = new TeenAgent::TeenAgentEngine(syst, desc);
-		}
-		return desc != 0;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
+		*engine = new TeenAgent::TeenAgentEngine(syst, desc);
+		return Common::kNoError;
 	}
 
 	static Common::String generateGameStateFileName(const char *target, int slot) {
diff --git a/engines/testbed/metaengine.cpp b/engines/testbed/metaengine.cpp
index 6b49b347ae..ea774f5f91 100644
--- a/engines/testbed/metaengine.cpp
+++ b/engines/testbed/metaengine.cpp
@@ -35,10 +35,9 @@ public:
 		return "testbed";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription * /* desc */) const override {
-		// Instantiate Engine even if the game data is not found.
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription * /* desc */) const override {
 		*engine = new Testbed::TestbedEngine(syst);
-		return true;
+		return Common::kNoError;
 	}
 
 	const Common::AchievementsInfo getAchievementsInfo(const Common::String &target) const override {
diff --git a/engines/tinsel/metaengine.cpp b/engines/tinsel/metaengine.cpp
index f95abe155f..8594acf36f 100644
--- a/engines/tinsel/metaengine.cpp
+++ b/engines/tinsel/metaengine.cpp
@@ -69,7 +69,7 @@ public:
 		return "tinsel";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
     bool hasFeature(MetaEngineFeature f) const override;
 	SaveStateList listSaves(const char *target) const override;
@@ -169,12 +169,9 @@ SaveStateList TinselMetaEngine::listSaves(const char *target) const {
 	return saveList;
 }
 
-bool TinselMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Tinsel::TinselGameDescription *gd = (const Tinsel::TinselGameDescription *)desc;
-	if (gd) {
-		*engine = new Tinsel::TinselEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error TinselMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Tinsel::TinselEngine(syst, (const Tinsel::TinselGameDescription *)desc);
+	return Common::kNoError;
 }
 
 int TinselMetaEngine::getMaximumSaveSlot() const { return 99; }
diff --git a/engines/titanic/metaengine.cpp b/engines/titanic/metaengine.cpp
index 13315642df..37d3b91983 100644
--- a/engines/titanic/metaengine.cpp
+++ b/engines/titanic/metaengine.cpp
@@ -52,7 +52,7 @@ public:
 	}
 
 	bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -79,11 +79,9 @@ bool Titanic::TitanicEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool TitanicMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Titanic::TitanicGameDescription *gd = (const Titanic::TitanicGameDescription *)desc;
-	*engine = new Titanic::TitanicEngine(syst, gd);
-
-	return gd != 0;
+Common::Error TitanicMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Titanic::TitanicEngine(syst, (const Titanic::TitanicGameDescription *)desc);
+	return Common::kNoError;
 }
 
 SaveStateList TitanicMetaEngine::listSaves(const char *target) const {
diff --git a/engines/toltecs/metaengine.cpp b/engines/toltecs/metaengine.cpp
index 788323f0f8..bcac79f5e0 100644
--- a/engines/toltecs/metaengine.cpp
+++ b/engines/toltecs/metaengine.cpp
@@ -50,7 +50,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
     SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -77,12 +77,9 @@ bool Toltecs::ToltecsEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool ToltecsMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Toltecs::ToltecsGameDescription *gd = (const Toltecs::ToltecsGameDescription *)desc;
-	if (gd) {
-		*engine = new Toltecs::ToltecsEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error ToltecsMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Toltecs::ToltecsEngine(syst, (const Toltecs::ToltecsGameDescription *)desc);
+	return Common::kNoError;
 }
 
 SaveStateList ToltecsMetaEngine::listSaves(const char *target) const {
diff --git a/engines/tony/metaengine.cpp b/engines/tony/metaengine.cpp
index dd2a019b2b..8d93c7e59b 100644
--- a/engines/tony/metaengine.cpp
+++ b/engines/tony/metaengine.cpp
@@ -58,7 +58,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -82,12 +82,9 @@ bool Tony::TonyEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool TonyMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Tony::TonyGameDescription *gd = (const Tony::TonyGameDescription *)desc;
-	if (gd) {
-		*engine = new Tony::TonyEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error TonyMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Tony::TonyEngine(syst, (const Tony::TonyGameDescription *)desc);
+	return Common::kNoError;
 }
 
 SaveStateList TonyMetaEngine::listSaves(const char *target) const {
diff --git a/engines/toon/metaengine.cpp b/engines/toon/metaengine.cpp
index 138484f5ab..f9b313fbea 100644
--- a/engines/toon/metaengine.cpp
+++ b/engines/toon/metaengine.cpp
@@ -35,7 +35,7 @@ public:
 	}
 
 	bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	int getMaximumSaveSlot() const override;
 	SaveStateList listSaves(const char *target) const override;
@@ -157,11 +157,9 @@ SaveStateDescriptor ToonMetaEngine::querySaveMetaInfos(const char *target, int s
 	return SaveStateDescriptor();
 }
 
-bool ToonMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new Toon::ToonEngine(syst, desc);
-	}
-	return desc != 0;
+Common::Error ToonMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Toon::ToonEngine(syst, desc);
+	return Common::kNoError;
 }
 
 #if PLUGIN_ENABLED_DYNAMIC(TOON)
diff --git a/engines/touche/metaengine.cpp b/engines/touche/metaengine.cpp
index 2127a137c4..149af10e83 100644
--- a/engines/touche/metaengine.cpp
+++ b/engines/touche/metaengine.cpp
@@ -36,7 +36,7 @@ public:
 	}
 
 	bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
 	void removeSaveState(const char *target, int slot) const override;
@@ -57,11 +57,9 @@ bool Touche::ToucheEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSubtitleOptions);
 }
 
-bool ToucheMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new Touche::ToucheEngine(syst, desc->language);
-	}
-	return desc != 0;
+Common::Error ToucheMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Touche::ToucheEngine(syst, desc->language);
+	return Common::kNoError;
 }
 
 SaveStateList ToucheMetaEngine::listSaves(const char *target) const {
diff --git a/engines/tsage/metaengine.cpp b/engines/tsage/metaengine.cpp
index 9e2edc2b90..eb695f46cd 100644
--- a/engines/tsage/metaengine.cpp
+++ b/engines/tsage/metaengine.cpp
@@ -77,11 +77,9 @@ public:
 		}
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
-		if (desc) {
-			*engine = new TsAGE::TSageEngine(syst, (const TsAGE::tSageGameDescription *)desc);
-		}
-		return desc != 0;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
+		*engine = new TsAGE::TSageEngine(syst, (const TsAGE::tSageGameDescription *)desc);
+		return Common::kNoError;
 	}
 
 	static Common::String generateGameStateFileName(const char *target, int slot) {
diff --git a/engines/tucker/metaengine.cpp b/engines/tucker/metaengine.cpp
index 068cb4a5be..d63e33dcca 100644
--- a/engines/tucker/metaengine.cpp
+++ b/engines/tucker/metaengine.cpp
@@ -50,11 +50,9 @@ public:
 		}
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
-		if (desc) {
-			*engine = new Tucker::TuckerEngine(syst, desc->language, desc->flags);
-		}
-		return desc != nullptr;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
+		*engine = new Tucker::TuckerEngine(syst, desc->language, desc->flags);
+		return Common::kNoError;
 	}
 
     SaveStateList listSaves(const char *target) const override {
diff --git a/engines/twine/metaengine.cpp b/engines/twine/metaengine.cpp
index fdaa7bea3c..ea66ca31d5 100644
--- a/engines/twine/metaengine.cpp
+++ b/engines/twine/metaengine.cpp
@@ -45,18 +45,16 @@ public:
 		return 6;
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
-		if (desc) {
-			TwineGameType gameType = TwineGameType::GType_LBA;
-			const Common::String gameId = desc->gameId;
-			if (gameId == "lba") {
-				gameType = TwineGameType::GType_LBA;
-			} else if (gameId == "lba2") {
-				gameType = TwineGameType::GType_LBA2;
-			}
-			*engine = new TwinE::TwinEEngine(syst, desc->language, desc->flags, gameType);
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
+		TwineGameType gameType = TwineGameType::GType_LBA;
+		const Common::String gameId = desc->gameId;
+		if (gameId == "lba") {
+			gameType = TwineGameType::GType_LBA;
+		} else if (gameId == "lba2") {
+			gameType = TwineGameType::GType_LBA2;
 		}
-		return desc != nullptr;
+		*engine = new TwinE::TwinEEngine(syst, desc->language, desc->flags, gameType);
+		return Common::kNoError;
 	}
 
 	Common::Array<Common::Keymap *> initKeymaps(const char *target) const override;
diff --git a/engines/ultima/metaengine.cpp b/engines/ultima/metaengine.cpp
index 3ea84c1487..10d0a63c78 100644
--- a/engines/ultima/metaengine.cpp
+++ b/engines/ultima/metaengine.cpp
@@ -41,34 +41,32 @@ const char *UltimaMetaEngine::getName() const {
 	return "ultima";
 }
 
-bool UltimaMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error UltimaMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const Ultima::UltimaGameDescription *gd = (const Ultima::UltimaGameDescription *)desc;
-	if (gd) {
-		switch (gd->gameId) {
+	switch (gd->gameId) {
 #ifndef RELEASE_BUILD
-		case Ultima::GAME_ULTIMA1:
-			*engine = new Ultima::Shared::UltimaEarlyEngine(syst, gd);
-			break;
+	case Ultima::GAME_ULTIMA1:
+		*engine = new Ultima::Shared::UltimaEarlyEngine(syst, gd);
+		break;
 #endif
-		case Ultima::GAME_ULTIMA4:
-			*engine = new Ultima::Ultima4::Ultima4Engine(syst, gd);
-			break;
-		case Ultima::GAME_ULTIMA6:
-		case Ultima::GAME_MARTIAN_DREAMS:
-		case Ultima::GAME_SAVAGE_EMPIRE:
-			*engine = new Ultima::Nuvie::NuvieEngine(syst, gd);
-			break;
-		case Ultima::GAME_ULTIMA8:
-		case Ultima::GAME_CRUSADER_REG:
-		case Ultima::GAME_CRUSADER_REM:
-			*engine = new Ultima::Ultima8::Ultima8Engine(syst, gd);
-			break;
+	case Ultima::GAME_ULTIMA4:
+		*engine = new Ultima::Ultima4::Ultima4Engine(syst, gd);
+		break;
+	case Ultima::GAME_ULTIMA6:
+	case Ultima::GAME_MARTIAN_DREAMS:
+	case Ultima::GAME_SAVAGE_EMPIRE:
+		*engine = new Ultima::Nuvie::NuvieEngine(syst, gd);
+		break;
+	case Ultima::GAME_ULTIMA8:
+	case Ultima::GAME_CRUSADER_REG:
+	case Ultima::GAME_CRUSADER_REM:
+		*engine = new Ultima::Ultima8::Ultima8Engine(syst, gd);
+		break;
 
-		default:
-			error("Unsupported ultima engine game specified");
-		}
+	default:
+		return Common::kUnsupportedGameidError;
 	}
-	return gd != 0;
+	return Common::kNoError;
 }
 
 int UltimaMetaEngine::getMaximumSaveSlot() const {
diff --git a/engines/ultima/metaengine.h b/engines/ultima/metaengine.h
index 3297d0a738..523b9034eb 100644
--- a/engines/ultima/metaengine.h
+++ b/engines/ultima/metaengine.h
@@ -37,7 +37,7 @@ private:
 public:
 	const char *getName() const override;
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	int getMaximumSaveSlot() const override;
 
 	/**
diff --git a/engines/voyeur/metaengine.cpp b/engines/voyeur/metaengine.cpp
index c59ad1ff3f..5c4d4923a5 100644
--- a/engines/voyeur/metaengine.cpp
+++ b/engines/voyeur/metaengine.cpp
@@ -60,7 +60,7 @@ public:
 	}
 
     bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
 	void removeSaveState(const char *target, int slot) const override;
@@ -84,12 +84,9 @@ bool Voyeur::VoyeurEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool VoyeurMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const Voyeur::VoyeurGameDescription *gd = (const Voyeur::VoyeurGameDescription *)desc;
-	if (gd) {
-		*engine = new Voyeur::VoyeurEngine(syst, gd);
-	}
-	return gd != 0;
+Common::Error VoyeurMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Voyeur::VoyeurEngine(syst, (const Voyeur::VoyeurGameDescription *)desc);
+	return Common::kNoError;
 }
 
 SaveStateList VoyeurMetaEngine::listSaves(const char *target) const {
diff --git a/engines/wage/metaengine.cpp b/engines/wage/metaengine.cpp
index f9627d0420..b9dda6af5b 100644
--- a/engines/wage/metaengine.cpp
+++ b/engines/wage/metaengine.cpp
@@ -43,7 +43,7 @@ public:
 		return "wage";
 	}
 
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	bool hasFeature(MetaEngineFeature f) const override;
 	SaveStateList listSaves(const char *target) const override;
@@ -66,11 +66,9 @@ bool Wage::WageEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool WageMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	if (desc) {
-		*engine = new Wage::WageEngine(syst, desc);
-	}
-	return desc != 0;
+Common::Error WageMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new Wage::WageEngine(syst, desc);
+	return Common::kNoError;
 }
 
 SaveStateList WageMetaEngine::listSaves(const char *target) const {
diff --git a/engines/wintermute/metaengine.cpp b/engines/wintermute/metaengine.cpp
index 07504b9d9f..f283dbe017 100644
--- a/engines/wintermute/metaengine.cpp
+++ b/engines/wintermute/metaengine.cpp
@@ -57,34 +57,29 @@ public:
 		return "wintermute";
 	}
 
-    bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
-		assert(syst);
-		assert(engine);
+    Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override {
 		const WMEGameDescription *gd = (const WMEGameDescription *)desc;
 
 #ifndef ENABLE_FOXTAIL
 		if (gd->targetExecutable >= FOXTAIL_OLDEST_VERSION && gd->targetExecutable <= FOXTAIL_LATEST_VERSION) {
-			Engine::errorUnsupportedGame(_("FoxTail support is not compiled in"));
-			return false;
+			return Common::Error(Common::kUnsupportedGameidError, _s("FoxTail support is not compiled in"));
 		}
 #endif
 
 #ifndef ENABLE_HEROCRAFT
 		if (gd->targetExecutable == WME_HEROCRAFT) {
-			Engine::errorUnsupportedGame(_("Hero Craft support is not compiled in"));
-			return false;
+			return Common::Error(Common::kUnsupportedGameidError, _s("Hero Craft support is not compiled in"));
 		}
 #endif
 
 #ifndef ENABLE_WME3D
 		if (gd->adDesc.flags & GF_3D) {
-			Engine::errorUnsupportedGame(_("Wintermute3D support is not compiled in"));
-			return false;
+			return Common::Error(Common::kUnsupportedGameidError, _s("Wintermute3D support is not compiled in"));
 		}
 #endif
 
 		*engine = new Wintermute::WintermuteEngine(syst, gd);
-		return true;
+		return Common::kNoError;
 	}
 
 	bool hasFeature(MetaEngineFeature f) const override {
diff --git a/engines/xeen/metaengine.cpp b/engines/xeen/metaengine.cpp
index 77e38a282d..147488dbe2 100644
--- a/engines/xeen/metaengine.cpp
+++ b/engines/xeen/metaengine.cpp
@@ -75,7 +75,7 @@ public:
 	}
 
 	bool hasFeature(MetaEngineFeature f) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
 	void removeSaveState(const char *target, int slot) const override;
@@ -101,7 +101,7 @@ bool Xeen::XeenEngine::hasFeature(EngineFeature f) const {
 		(f == kSupportsSavingDuringRuntime);
 }
 
-bool XeenMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+Common::Error XeenMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const Xeen::XeenGameDescription *gd = (const Xeen::XeenGameDescription *)desc;
 
 	switch (gd->gameID) {
@@ -114,10 +114,10 @@ bool XeenMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGame
 		*engine = new Xeen::SwordsOfXeen::SwordsOfXeenEngine(syst, gd);
 		break;
 	default:
-		error("Invalid game");
+		return Common::kUnsupportedGameidError;
 	}
 
-	return true;
+	return Common::kNoError;
 }
 
 SaveStateList XeenMetaEngine::listSaves(const char *target) const {
diff --git a/engines/zvision/metaengine.cpp b/engines/zvision/metaengine.cpp
index f119c53bd1..bcdc9afa38 100644
--- a/engines/zvision/metaengine.cpp
+++ b/engines/zvision/metaengine.cpp
@@ -59,7 +59,7 @@ public:
 
     bool hasFeature(MetaEngineFeature f) const override;
 	Common::KeymapArray initKeymaps(const char *target) const override;
-	bool createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
+	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;
 
 	SaveStateList listSaves(const char *target) const override;
 	int getMaximumSaveSlot() const override;
@@ -232,12 +232,9 @@ Common::KeymapArray ZVisionMetaEngine::initKeymaps(const char *target) const {
 	return keymaps;
 }
 
-bool ZVisionMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
-	const ZVision::ZVisionGameDescription *gd = (const ZVision::ZVisionGameDescription *)desc;
-	if (gd) {
-		*engine = new ZVision::ZVision(syst, gd);
-	}
-	return gd != 0;
+Common::Error ZVisionMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
+	*engine = new ZVision::ZVision(syst, (const ZVision::ZVisionGameDescription *)desc);
+	return Common::kNoError;
 }
 
 SaveStateList ZVisionMetaEngine::listSaves(const char *target) const {


Commit: ba8551b3aecc876158e3dfd8b66407efb5b7c4e5
    https://github.com/scummvm/scummvm/commit/ba8551b3aecc876158e3dfd8b66407efb5b7c4e5
Author: Cameron Cawley (ccawley2011 at gmail.com)
Date: 2020-12-04T20:57:14Z

Commit Message:
AGOS: Allow detecting games from disabled subengines

Changed paths:
    engines/agos/POTFILES
    engines/agos/detection.cpp
    engines/agos/detection_tables.h
    engines/agos/metaengine.cpp


diff --git a/engines/agos/POTFILES b/engines/agos/POTFILES
index 1f52d7df95..95027f8fe4 100644
--- a/engines/agos/POTFILES
+++ b/engines/agos/POTFILES
@@ -1,3 +1,4 @@
 engines/agos/saveload.cpp
 engines/agos/animation.cpp
+engines/agos/metaengine.cpp
 engines/agos/midi.cpp
diff --git a/engines/agos/detection.cpp b/engines/agos/detection.cpp
index d02ef0ffb8..b12156b71b 100644
--- a/engines/agos/detection.cpp
+++ b/engines/agos/detection.cpp
@@ -46,13 +46,11 @@ static const PlainGameDescriptor agosGames[] = {
 	{"waxworks", "Waxworks"},
 	{"simon1", "Simon the Sorcerer 1"},
 	{"simon2", "Simon the Sorcerer 2"},
-#ifdef ENABLE_AGOS2
 	{"feeble", "The Feeble Files"},
 	{"dimp", "Demon in my Pocket"},
 	{"jumble", "Jumble"},
 	{"puzzle", "NoPatience"},
 	{"swampy", "Swampy Adventures"},
-#endif
 	{0, 0}
 };
 
diff --git a/engines/agos/detection_tables.h b/engines/agos/detection_tables.h
index 46e80851d3..17a3e7cebc 100644
--- a/engines/agos/detection_tables.h
+++ b/engines/agos/detection_tables.h
@@ -2551,7 +2551,6 @@ static const AGOSGameDescription gameDescriptions[] = {
 		GF_TALKIE | GF_WAVSFX
 	},
 
-#ifdef ENABLE_AGOS2
 	// The Feeble Files - English DOS Demo
 	{
 		{
@@ -3194,7 +3193,7 @@ static const AGOSGameDescription gameDescriptions[] = {
 		GID_SWAMPY,
 		GF_OLD_BUNDLE | GF_TALKIE
 	},
-#endif
+
 	{ AD_TABLE_END_MARKER, 0, 0, 0 }
 };
 
diff --git a/engines/agos/metaengine.cpp b/engines/agos/metaengine.cpp
index 58aca57e47..2d2fd3098a 100644
--- a/engines/agos/metaengine.cpp
+++ b/engines/agos/metaengine.cpp
@@ -24,6 +24,7 @@
 #include "common/savefile.h"
 #include "common/system.h"
 #include "common/installshield_cab.h"
+#include "common/translation.h"
 
 #include "engines/advancedDetector.h"
 #include "engines/obsolete.h"
@@ -97,6 +98,10 @@ Common::Error AgosMetaEngine::createInstance(OSystem *syst, Engine **engine, con
 		else
 			*engine = new AGOS::AGOSEngine_PuzzlePack(syst, gd);
 		break;
+#else
+	case AGOS::GType_FF:
+	case AGOS::GType_PP:
+		return Common::Error(Common::kUnsupportedGameidError, _s("AGOS 2 support is not compiled in"));
 #endif
 	default:
 		return Common::kUnsupportedGameidError;