Storyboard Crash OSX - objective-c

Question

I'm seeing this crash happen very randomly:
Fatal Exception: NSInvalidArgumentException
*** setObjectForKey: object cannot be nil (key: NSViewController-Qmf-WE-Bmb)
0 CoreFoundation 0x7fff95e504da __exceptionPreprocess
1 libobjc.A.dylib 0x7fff923eef7e objc_exception_throw
2 CoreFoundation 0x7fff95d4a414 -[__NSDictionaryM setObject:forKey:]
3 AppKit 0x7fff9857f917 -[NSStoryboard nibForControllerWithIdentifier:]
4 AppKit 0x7fff9857fc11 -[NSStoryboard instantiateControllerWithIdentifier:]
5 AppKit 0x7fff982e733b -[NSStoryboardSegueTemplate _perform:]
6 AppKit 0x7fff983345d7 -[NSViewController performSegueWithIdentifier:sender:]
7 libdispatch.dylib 0x7fff8e5cc93d _dispatch_call_block_and_release
8 libdispatch.dylib 0x7fff8e5c140b _dispatch_client_callout
9 libdispatch.dylib 0x7fff8e5d4c1c _dispatch_main_queue_callback_4CF
10 CoreFoundation 0x7fff95e059e9 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__
11 CoreFoundation 0x7fff95dc48dd __CFRunLoopRun
12 CoreFoundation 0x7fff95dc3ed8 CFRunLoopRunSpecific
13 HIToolbox 0x7fff99b4b935 RunCurrentEventLoopInMode
14 HIToolbox 0x7fff99b4b76f ReceiveNextEventCommon
15 HIToolbox 0x7fff99b4b5af _BlockUntilNextEventMatchingListInModeWithFilter
16 AppKit 0x7fff97e3bdf6 _DPSNextEvent
17 AppKit 0x7fff97e3b226 -[NSApplication _nextEventMatchingEventMask:untilDate:inMode:dequeue:]
18 AppKit 0x7fff97e2fd80 -[NSApplication run]
19 AppKit 0x7fff97df9368 NSApplicationMain
20 libdyld.dylib 0x7fff8c6875ad start
I've verified that the segue identifier is correct and that the storyboard exists and contains the segue. I've also verified that there is a view controller with ID: Qmf-WE-Bmb.
Any clues why this would happen? Does this mean the source VC is deallocated or that its failing to load the destination VC?

Answer 1

In case anyone hits the same issue, I circumvented the crash by replacing performSegueWithIdentifier: with a custom function on my base controller:
- (void)performManualSegueWithControllerID:(NSString *)identifier {
if ([NSThread isMainThread]) {
NSViewController *controller = [self.storyboard instantiateControllerWithIdentifier:identifier];
if (controller) {
MyCustomAnimator *animator = [[MyCustomAnimator alloc] init];
[animator setAnimateVertically:NO];
[self prepareForManualSegueToController:controller];
[self presentViewController:controller animator:animator];
} else {
// Some Error
}
} else {
[self performSelectorOnMainThread:#selector(performManualSegueWithControllerID:)
withObject:identifier
waitUntilDone:NO];
}
}
- (void)prepareForManualSegueToController:(NSViewController *)controller {
}