Core Data -existingObjectWithID:error: causes error 133000

Question

My app uses Core Data (with some help of Magical Record) and is rather heavily multithreaded using NSOperation.

Of course I am very careful to only pass aro

Answer 1

I encountered this issue, even though the objectID was not temporary. This was because I foolishly forgot to set the parent on the child MOC.

childManagedObjectContext.parent = managedObjectContext