Xcode 6.1 Swift Thread 1 Sigabrt Error

Question

2015-04-14 23:35:17.143 Yellow Ninja 2.0[12492:594324] -[Yellow_Ninja_2_0.ACWallGenerator generatewall]: unrecognized selector sent to instance 0x7faf38fb7ce0 2015-04-14 23:35:17.146 Yellow Ninja 2.0[12492:594324] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Yellow_Ninja_2_0.ACWallGenerator generatewall]: unrecognized selector sent to instance 0x7faf38fb7ce0' * First throw call stack: ( 0 CoreFoundation 0x000000010fc77f35 exceptionPreprocess + 165 1 libobjc.A.dylib
0x0000000111bb4bb7 objc_exception_throw + 45 2 CoreFoundation
0x000000010fc7f04d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205 3 CoreFoundation 0x000000010fbd727c ___forwarding_ + 988 4 CoreFoundation 0x000000010fbd6e18 _CF_forwarding_prep_0 + 120 5 Foundation
0x00000001102ef2b4 NSFireTimer + 83 6 CoreFoundation
0x000000010fbdff64 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION + 20 7 CoreFoundation 0x000000010fbdfb25 __CFRunLoopDoTimer + 1045 8 CoreFoundation 0x000000010fba2e5d __CFRunLoopRun + 1901 9 CoreFoundation
0x000000010fba2486 CFRunLoopRunSpecific + 470 10 GraphicsServices
0x00000001170249f0 GSEventRunModal + 161 11 UIKit
0x00000001108fc420 UIApplicationMain + 1282 12 Yellow Ninja 2.0
0x000000010fa7a5be top_level_code + 78 13 Yellow Ninja 2.0
0x000000010fa7a5fa main + 42 14 libdyld.dylib
0x00000001123a0145 start + 1 15 ???
0x0000000000000001 0x0 + 1 ) libc++abi.dylib: terminating with uncaught exception of type NSException (lldb)

This is the error message that came up whenever I try to run my app. Any suggestions please? It says "InvalidArgumentException"??? Thanks!

Answer 1

You have set up a timer to call generatewall when it fires. But either you have no generatewall method — for example, if it takes a parameter, then it is called generatewall:, with a colon — or you have neglected to expose that method to Objective-C.