This demonstrates the problem I am having with ti.worker module. The app causes this error when run: The application has crashed with an uncaught exception 'NSInvalidArgumentException'. [DEBUG] Reason: [DEBUG] *** -[NSURL initFileURLWithPath:]: nil string parameter [DEBUG] Stack trace: [DEBUG] 0 CoreFoundation 0x03475012 __exceptionPreprocess + 178 [DEBUG] 1 libobjc.A.dylib 0x03082e7e objc_exception_throw + 44 [DEBUG] 2 CoreFoundation 0x03474deb +[NSException raise:format:] + 139 [DEBUG] 3 Foundation 0x00cb0281 -[NSURL(NSURL) initFileURLWithPath:] + 94 [DEBUG] 4 Foundation 0x00cb020b +[NSURL(NSURL) fileURLWithPath:] + 67 [DEBUG] 5 Swap-A-Doodle 0x00046259 -[KrollBridge evalFileOnThread:context:] + 265 [DEBUG] 6 libobjc.A.dylib 0x03096705 -[NSObject performSelector:withObject:withObject:] + 77 [DEBUG] 7 Swap-A-Doodle 0x0004bbd1 -[KrollInvocation invoke:] + 145 [DEBUG] 8 Swap-A-Doodle 0x0004e108 -[KrollContext invokeOnThread:method:withObject:callback:selector:] + 248 [DEBUG] 9 Swap-A-Doodle 0x00046a9d -[KrollBridge evalFile:callback:selector:] + 125 [DEBUG] 10 Swap-A-Doodle 0x000479b1 -[KrollBridge didStartNewContext:] + 2657 [DEBUG] 11 libobjc.A.dylib 0x030966b0 -[NSObject performSelector:withObject:] + 70 [DEBUG] 12 Swap-A-Doodle 0x0004f0ef -[KrollContext main] + 3199 [DEBUG] 13 Foundation 0x00ce40d5 -[NSThread main] + 76 [DEBUG] 14 Foundation 0x00ce4034 __NSThread__main__ + 1304 [DEBUG] 15 libsystem_c.dylib 0x977a1ed9 _pthread_start + 335 [DEBUG] 16 libsystem_c.dylib 0x977a56de thread_start + 34 [DEBUG] 2013-01-30 19:10:35.372 Swap-A-Doodle[24095:1da0b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSURL initFileURLWithPath:]: nil string parameter' [DEBUG] *** First throw call stack: [DEBUG] (0x3475012 0x3082e7e 0x3474deb 0xcb0281 0xcb020b 0x46259 0x3096705 0x4bbd1 0x4e108 0x46a9d 0x479b1 0x30966b0 0x4f0ef 0xce40d5 0xce4034 0x977a1ed9 0x977a56de)