-[NSObject(NSObject) doesNotRecognizeSelector:] crash when call -[ViewController prepareForSegue:sender:]

Question

I am using Crashlytics to detect the crashes in my app. I occasionally get the follow crash report.

The key crash point is -[NSObject(NSObject) doesNotRecognizeSelector:] and MyViewController.m line 596 -[MyViewController prepareForSegue:sender:]. I don't know what's the problem of that from the log. Is is possible a multi-threading issue? I am also using Parse SDK to retrieve the data from Parse cloud. And prepareForSegue:sender: method will be invoked when the user tap the disclosure indicator, it should run in main thread. Would you please give me some hint to troubleshoot this issue. Thanks in advance.

Here is how I call prepareForSegue:sender: method.

- (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath
{
    [self performSegueWithIdentifier:@"oneSegue" sender:indexPath];
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.identifier isEqualToString:@"oneSegue"]) {
        NSIndexPath *indexPath = (NSIndexPath*)sender;
        OneViewController *destViewController = segue.destinationViewController;
        OneClass* oneObject = self.array[indexPath.row];
        destViewController.objectName = oneObject.name;
    }
}

prepareForSegue:sender: method is triggered by accessoryButtonTappedForRowWithIndexPath: method. I can't see any other way to invoke prepareForSegue:sender: method. So I don't why indexPath.row causes the exception.

Fatal Exception NSInvalidArgumentException
-[UITableViewCell row]: unrecognized selector sent to instance 0x1f8a6dd0
0    CoreFoundation  __exceptionPreprocess + 162
1    libobjc.A.dylib     objc_exception_throw + 30
2    **CoreFoundation    -[NSObject(NSObject) doesNotRecognizeSelector:] + 170**
3    CoreFoundation  ___forwarding___ + 392
4    CoreFoundation  _CF_forwarding_prep_0 + 24
5    MyApp  
MyViewController.m line 596
**-[MyViewController prepareForSegue:sender:]**
6    UIKit   -[UIStoryboardSegueTemplate _perform:] + 128
7    UIKit   -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:] + 828
8    UIKit   -[UITableView _userSelectRowAtPendingSelectionIndexPath:] + 156
9 ...    Foundation  __NSFireDelayedPerform + 450
10   CoreFoundation  __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 14
11   CoreFoundation  __CFRunLoopDoTimer + 272
12   CoreFoundation  __CFRunLoopRun + 1232
13   CoreFoundation  CFRunLoopRunSpecific + 356
14   CoreFoundation  CFRunLoopRunInMode + 104
15   GraphicsServices    GSEventRunModal + 74
16   UIKit   UIApplicationMain + 1120
17   MyApp  
main.m line 16
main
18   libdyld.dylib   start
9 Threads
com.apple.main-thread Crashed
0 ...    libsystem_kernel.dylib  __pthread_kill + 8
1    libsystem_c.dylib   pthread_kill + 58
2    libsystem_c.dylib   abort + 94
3    libc++abi.dylib     abort_message + 74
4    libc++abi.dylib     default_terminate() + 24
5    libobjc.A.dylib     _objc_terminate() + 146
6    libc++abi.dylib     safe_handler_caller(void (*)()) + 78
7    libc++abi.dylib     std::terminate() + 19
8    libc++abi.dylib     __cxa_current_exception_type
9    libobjc.A.dylib     objc_exception_rethrow + 12
10   CoreFoundation  CFRunLoopRunSpecific + 456
11   CoreFoundation  CFRunLoopRunInMode + 104
12   GraphicsServices    GSEventRunModal + 74
13   UIKit   UIApplicationMain + 1120
14   MyApp  
main.m line 16
main
com.apple.libdispatch-manager
0 ...    libsystem_kernel.dylib  kevent64 + 24
1    libdispatch.dylib   _dispatch_mgr_invoke + 796
2    libdispatch.dylib   _dispatch_mgr_thread$VARIANT$mp + 35
WebThread
0 ...    libsystem_kernel.dylib  mach_msg_trap + 20
1    libsystem_kernel.dylib  mach_msg + 40
2    CoreFoundation  __CFRunLoopServiceMachPort + 128
3    CoreFoundation  __CFRunLoopRun + 882
4    CoreFoundation  CFRunLoopRunSpecific + 356
5    CoreFoundation  CFRunLoopRunInMode + 104
6    WebCore     RunWebThread(void*) + 444
7    libsystem_c.dylib   _pthread_start + 308
com.crashlytics.MachExceptionServer
0    libsystem_kernel.dylib  mach_msg_trap + 20
1    libsystem_kernel.dylib  mach_msg + 40
2    MyApp   CLSMachExceptionServer
3    libsystem_c.dylib   _pthread_start + 308
com.apple.NSURLConnectionLoader
0 ...    libsystem_kernel.dylib  mach_msg_trap + 20
1    libsystem_kernel.dylib  mach_msg + 40
2    CoreFoundation  __CFRunLoopServiceMachPort + 128
3    CoreFoundation  __CFRunLoopRun + 882
4    CoreFoundation  CFRunLoopRunSpecific + 356
5    CoreFoundation  CFRunLoopRunInMode + 104
6    Foundation  +[NSURLConnection(Loader) _resourceLoadLoop:] + 308
7    Foundation  __NSThread__main__ + 972
8    libsystem_c.dylib   _pthread_start + 308
Thread 5
0 ...    libsystem_kernel.dylib  mach_msg_trap + 20
1    libsystem_kernel.dylib  mach_msg + 40
2    CoreFoundation  __CFRunLoopServiceMachPort + 128
3    CoreFoundation  __CFRunLoopRun + 882
4    CoreFoundation  CFRunLoopRunSpecific + 356
5    CoreFoundation  CFRunLoopRunInMode + 104
6    Foundation  -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 254
7    Foundation  -[NSRunLoop(NSRunLoop) run] + 80
8    MyApp  
PF_AFURLConnectionOperation.m line 151
+[PF_AFURLConnectionOperation networkRequestThreadEntryPoint:]
9    Foundation  __NSThread__main__ + 972
10   libsystem_c.dylib   _pthread_start + 308
Thread 6
0 ...    libsystem_kernel.dylib  __psynch_cvwait + 24
1    libsystem_c.dylib   _pthread_cond_wait + 646
2    libsystem_c.dylib   pthread_cond_wait + 40
3    Foundation  -[NSCondition wait] + 194
4    MyApp  
PFCommandCache.m line 495
-[PFCommandCache runLoop]
5    Foundation  __NSThread__main__ + 972
6    libsystem_c.dylib   _pthread_start + 308
com.apple.CFSocket.private
0 ...    libsystem_kernel.dylib  __select + 20
1    CoreFoundation  __CFSocketManager + 678
2    libsystem_c.dylib   _pthread_start + 308
Thread 8
0 ...    libsystem_kernel.dylib  __workq_kernreturn + 8
1    libsystem_c.dylib   _pthread_workq_return + 18
2    libsystem_c.dylib   _pthread_wqthread + 365
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Answer 1

It is because in the view that you are opening up into, somewhere you are trying to call a method called row on a UITableViewCell.

You can see this in the first line of your crash log:

-[UITableViewCell row]: unrecognized selector sent to instance 0x1f8a6dd0

You should track down what object you are calling row on and make sure that you are calling it on the object that you think you are and not a UITableViewCell.