Your crash log gives you the answer:
2013-12-14 15:13:12.963 IFST[2448:70b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UITabBarController topViewController]: unrecognized selector sent to instance 0x8a6c290'
Somewhere you're sending topViewController
to the tab bar controller. It's not a navigation controller, so this method is not appropriate. Maybe selectedViewController
is the one you're looking for.