diff --git a/client/CPreGame.cpp b/client/CPreGame.cpp
index 345b0a1a6..1b4f55886 100644
--- a/client/CPreGame.cpp
+++ b/client/CPreGame.cpp
@@ -1119,7 +1119,7 @@ void SelectionTab::parseGames(const std::unordered_set<ResourceID> &files, bool
 	{
 		try
 		{
-			CLoadFile lf(*CResourceHandler::get()->getResourceName(file));
+			CLoadFile lf(*CResourceHandler::get()->getResourceName(file), minSupportedVersion);
 			lf.checkMagicBytes(SAVEGAME_MAGIC);
 // 			ui8 sign[8];
 // 			lf >> sign;
diff --git a/client/Client.cpp b/client/Client.cpp
index fea87d2a0..be50f9f0a 100644
--- a/client/Client.cpp
+++ b/client/Client.cpp
@@ -244,7 +244,7 @@ void CClient::loadGame( const std::string & fname )
 
 		unique_ptr<CLoadFile> loader;
 		{
-			CLoadIntegrityValidator checkingLoader(clientSaveName, controlServerSaveName);
+			CLoadIntegrityValidator checkingLoader(clientSaveName, controlServerSaveName, minSupportedVersion);
 			loadCommonState(checkingLoader);
 			loader = checkingLoader.decay();
 		}
diff --git a/lib/CModHandler.h b/lib/CModHandler.h
index cbe6397a5..fa0050ea5 100644
--- a/lib/CModHandler.h
+++ b/lib/CModHandler.h
@@ -41,6 +41,18 @@ class CIdentifierStorage
 	{
 		si32 id;
 		std::string scope; /// scope in which this ID located
+
+
+		template <typename Handler> void serialize(Handler &h, const int version)
+		{
+			if(version >= 744)
+				h & id & scope;
+			else if(h.saving)
+			{
+				logGlobal->warnStream() << "Save compatibility, making object data with id -1 (can this happen?)";
+				id = -1;
+			}
+		}
 	};
 
 	std::multimap<std::string, ObjectData > registeredObjects;
@@ -72,6 +84,12 @@ public:
 
 	/// called at the very end of loading to check for any missing ID's
 	void finalize();
+
+	template <typename Handler> void serialize(Handler &h, const int version)
+	{
+		if(version >= 744)
+			h & registeredObjects;
+	}
 };
 
 /// class used to load all game data into handlers. Used only during loading
@@ -249,5 +267,9 @@ public:
 	template <typename Handler> void serialize(Handler &h, const int version)
 	{
 		h & allMods & activeMods & settings & modules;
+		if(version >= 744)
+			h & identifiers;
+		else
+			logGlobal->warnStream() << "Savegame compatibility mode, omitting identifiers in modhandler. Related bugs will persist.";
 	}
 };
diff --git a/lib/Connection.h b/lib/Connection.h
index 79f276e32..b0c6a53f5 100644
--- a/lib/Connection.h
+++ b/lib/Connection.h
@@ -28,7 +28,8 @@
 #include "mapping/CCampaignHandler.h" //for CCampaignState
 #include "rmg/CMapGenerator.h" // for CMapGenOptions
 
-const ui32 version = 743;
+const ui32 version = 744;
+const ui32 minSupportedVersion = 743;
 
 class CConnection;
 class CGObjectInstance;
@@ -798,6 +799,13 @@ public:
 		for(typename std::map<T1,T2>::const_iterator i=data.begin();i!=data.end();i++)
 			*this << i->first << i->second;
 	}
+	template <typename T1, typename T2>
+	void saveSerializable(const std::multimap<T1, T2> &data)
+	{
+		*this << ui32(data.size());
+		for(typename std::map<T1, T2>::const_iterator i = data.begin(); i != data.end(); i++)
+			*this << i->first << i->second;
+	}
 	template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
 	void saveSerializable(const boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> &data)
 	{
@@ -1198,6 +1206,19 @@ public:
 			*this >> data[t];
 		}
 	}
+	template <typename T1, typename T2>
+	void loadSerializable(std::multimap<T1, T2> &data)
+	{
+		READ_CHECK_U32(length);
+		data.clear();
+		T1 key;
+		T2 value;
+		for(ui32 i = 0; i < length; i++)
+		{
+			*this >> key >> value;
+			data.insert(std::pair<T1, T2>(std::move(key), std::move(value)));
+		}
+	}
 	void loadSerializable(std::string &data)
 	{
 		READ_CHECK_U32(length);
diff --git a/server/CVCMIServer.cpp b/server/CVCMIServer.cpp
index 2c41222d4..fe51e362a 100644
--- a/server/CVCMIServer.cpp
+++ b/server/CVCMIServer.cpp
@@ -477,7 +477,7 @@ void CVCMIServer::loadGame()
 // 	}
 
 	{
-		CLoadFile lf(*CResourceHandler::get()->getResourceName(ResourceID(fname, EResType::SERVER_SAVEGAME)));
+		CLoadFile lf(*CResourceHandler::get()->getResourceName(ResourceID(fname, EResType::SERVER_SAVEGAME)), minSupportedVersion);
 		gh.loadCommonState(lf);
 		lf >> gh;
 	}