The only thing I can think of is that somehow you have a schema mismatch between the development and production versions of Cloudkit. Are you doing any Cloudkit syncing? Sorry I can't be of much more help.

I had to explicitly put in function parameter for ModelContainer. So change: .modelContainer(try! ModelContainer(for: Closet.self, config)) to: .modelContainer(try! ModelContainer(for: Closet.self, configurations: config))

I'm having this same problem. Did you manage to find where this data is kept?