[bug] UINavigationController Zombie

1-CompleteLoginVC.mm

-(void)navigateToMainMenu:(UINavigationController *)mainMenuViewController
{
    id<HJDateOfBirthSurveyLogger> logger = self.dobSurveyLogger;
    
    dispatch_async(dispatch_get_main_queue(), ^void()
    {
        [logger logNavigatingToMainMenu];
        
        UIWindow *window = [UIApplication sharedApplication].keyWindow;

        [UIView transitionFromView: [window.subviews lastObject]
                            toView: mainMenuViewController.view
                          duration: 0.7
                           options: UIViewAnimationOptionTransitionFlipFromLeft
                        completion: ^(BOOL finished){
                            window.rootViewController = mainMenuViewController;
                        }];

        [SVProgressHUD dismiss];
    });
}

2-MainMenuVC.mm

-(void)viewDidAppear:(BOOL)animated 
{
    [super viewDidAppear:animated];
    BOOL shouldSkipMenu = .....;
    
    if(shouldSkipMenu) {
        UIViewController* controller = [self.storyboard instantiateViewControllerWithIdentifier:@"IntroController"];
        [self presentViewController:controller 
                           animated:YES 
                         completion:^() {
            // invalidate shouldSkipMenu condition
        }];
    }
}

3-WarningOnAddingIntroController.txt

Warning: Attempt to present <HLJIntroPageViewController: 0x1449c0c00> on <HLJMainMenuViewController: 0x1445f3b80> whose view is not in the window hierarchy!

4-IntroVC.mm

-(void)dismiss
{
    [self dismissViewControllerAnimated: YES
                             completion: ^void() { /*IDLE*/ } ];
}

5-CrashOnDismissing.txt

2015-03-30 19:17:53.231 healthjoy-branded[604:126441] Presenting view controllers on detached view controllers is discouraged <HLJMainMenuViewController: 0x14671ca00>.