Hoping someone can shed some light on what I might be doing wrong here.

Trying to add an "event" to a list of events, represented by a one to many (inverse) relationship:

MyEvents <--->> Event

This is the code:

    MyEvents *myEvents = (MyEvents *)[NSEntityDescription insertNewObjectForEntityForName:@"MyEvents" inManagedObjectContext:context];

NSLog(@"MYEVENTS: %@", myEvents);
NSLog(@"EVENT: %@", event);

[myEvents addEventObject:event];

My context is fine, and both the myEvents and event print perfectly valid information.

When I try to add the event that I have (which is passed into this view controller, having been retrieved from core data previously) with this code

[myEvents addEventObject:event];

It falls over with

*** -[NSComparisonPredicate evaluateWithObject:]: message sent to deallocated instance

MyEvents and Event are just the default generated code. MyEvents contains only the relationship to event.

Thanks.