NSInvalidArgumentException on pushingViewController


Hello there,
first of all thank you so much for the amazing Book. I’m Italian, and despite the problems with foreign languages, I found in this books what seems pratically impossible to found in my country: a pratical way to learn. So, again, really thank you.

At the moment I’m freezed on a strange exception…using (without experience) breakpoints to focus the “guilty code line”, I think that the exception happen when, in ItemDetailViewController.m:

[[self navigationController] pushViewController:navController animated:YES];

Thenm the following message is returned in the console:

*** Terminating app due to uncaught exception ‘NSInvalidArgumentException’, reason: ‘-[UINavigationTransitionView isSystemItem]: unrecognized selector sent to instance 0x6d8f070’
*** First throw call stack:
(0x13c1052 0x1552d0a 0x13c2ced 0x1327f00 0x1327ce2 0x7a716 0x7ac8c 0x7e21f 0xf1a38 0xf15a4 0xeb556 0x2945 0x13c2ec9 0x1b5c2 0x256d54 0x13c2ec9 0x1b5c2 0x1b55a 0xc0b76 0xc103f 0xc02fe 0x40a30 0x40c56 0x27384 0x1aaa9 0x12abfa9 0x13951c5 0x12fa022 0x12f890a 0x12f7db4 0x12f7ccb 0x12aa879 0x12aa93e 0x18a9b 0x209b 0x2045)
terminate called throwing an exceptionsharedlibrary apply-load-rules all
Current language: auto; currently objective-c

Anyone could help me to carry on this “ios-learn” way?