2441856

zomgwtf.m

            // In your answer, you have this:
            
            NSManagedObjectID *objectID = [person objectID];

            dispatch_async(dispatch_get_main_queue(), ^{

                //update your UI here
                Person *thePerson = (Person *)[[delegate managedObjectContext] objectWithID:objectID];
                self.myUIElement.text = person.firstname;

            });
            
            //Change to:
            
            NSString *firstName = person.firstname;
            dispatch_async(dispatch_get_main_queue(), ^{
                //update your UI here
                self.myUIElement.text = firstName;

            });
            
            // Safe!
            // Less complexity!
            // No need to do ANY core data operations on the UI thread!
            // Does not need to assume anything about [delegate managedObjectContext]!