Better loading of stuff

core/src/com/unciv/models/ruleset/Ruleset.kt

@@ -71,6 +71,7 @@ class Ruleset {
         unitPromotions.putAll(ruleset.unitPromotions)
         units.putAll(ruleset.units)
         for(unitToRemove in ruleset.modOptions.unitsToRemove) units.remove(unitToRemove)
+        mods += ruleset.mods
     }
 
     fun clear() {

core/src/com/unciv/ui/mapeditor/MapEditorScreen.kt

@@ -64,7 +64,9 @@ class MapEditorScreen(): CameraStageBaseScreen() {
 
         gameSetupInfo.gameParameters = scenario.gameParameters
 
-        ruleset = RulesetCache.getComplexRuleset(scenario.gameParameters)
+        // Since the ruleset is referenced directly from other places, we can't just replace it directly
+        ruleset.clear()
+        ruleset.add(RulesetCache.getComplexRuleset(scenario.gameParameters))
         initialize()
     }