I am occasionally seeing crashes with a stack trace like this:
0 libobjc.A.dylib 0x97dc0edb objc_msgSend + 27 1 com.apple.CoreData 0x97edcdc2 -[_PFManagedObj
i has another solution so solve that bug. In examples, MOC properties for ARC looks like (readonly,strong,nonatomic)
After weeks of dancing about that time-to-time crash i got solution for osx (just remove nonatomic).
Now it perfect, all crashes go out.