Migrating Blueprints Based on Migrated C++ Code: Bluprint could not be loaded because it derives from an invalid class. Check to make sure the parent class for this blueprint hasn't been removed!

[Rejji]

Use a Core redirect using MatchSubString modifier to map all items from one name to another:

[CoreRedirects]
+ClassRedirects=(OldName=“/Script/RPGRulesCPP”,NewName=“/Script/ADV_MOBA”,MatchSubstring=true)

Core Redirects