I\'m trying to serialize my Cart object which has an NSMutableArray of items in it but getting an:
NSMutableArray
*** Terminating app due to uncaught exception \
This line: [itemsToSerialize addObject:item]; should be [itemsToSerialize addObject:itemDict];. The result is that you're trying to serialize an array of the items themselves, which gives the exception you're seeing.
[itemsToSerialize addObject:item];
[itemsToSerialize addObject:itemDict];