Heres the problem... I Have an app in the app store, which uses core data... I have been updating my model correctly (using versions etc) but Just recently I have accidental
For anyone showing up on this question who is not trying to migrate a core data model to another this error can also show up if you are trying to save data to core data that has some values in your entity not being set. Make sure all your data variables are being set and set correctly to avoid this error that dreams of MacBook Pros riding unicorns may live forever in your reality!