I am creating database with Core Data in ios. I set up unique constraint in my conversation table. but after removing it I am getting error namely "In the uniqueness constraints attribute for entity Conversation, comma is not valid property". I looked every field in my DataModel.xcdatamodeld but not find any solution.
Its looks like a bug in Xcode 8. I have deleted all attributes from an entity, cleaned project and created attribute again and the error gone. May this will help someone.