Exception thrown in NSOrderedSet generated accessors

Question

On my Lion app, I have this data model:

The relationship subitem

Answer 1

It seems that if you link the parent with the child by setting the parent to the child and not the other way around it works without crashing.

So if you do:

[child setParent:parent]

instead of

[parent setChildObects:child]

It should work, at least it works on iOS 7 and didn't had any problems with the relationship.