Core Data: Could not cast value of type 'MyType_MyType_2' to MyType

Question

I have an Objective-C model class MyType. This class is used in Swift code:

NSEntityDescription.insertNewObjectForEntit         


        

Answer 1

I had mistakenly set a "parent entity" in one of my entities in the data model inspector in the entity section. I mistakenly thought that referred to the destination of a one-to-many relationship.

Setting it back to "no parent entity" fixed the problem, although I did have to delete and reinstall the app in the simulator to deal with the messed up core data database.