“[something copyWithZone:]: unrecognized selector sent to instance” when using Bindings / Core Data

Question

(self asking and self-answering because I spent hours on the web looking for this, and most of the resources all say \"I solved it in the end\" without giving an explanation

Answer 1

I would also like to post here because I had a similar issue with the same type of thing

empty defined object:

Wrong code:

@property (nonatomic, copy, readwrite) MSender * sender;

this should trow a compile error because with reference counting Xcode has no idea how to copy my object. Instead it fails at run time...

Write code:

@property (nonatomic, strong, readwrite) MSender * sender;

Hope it helps someone.