PhotoBomber[3396:53988] Unbalanced calls to begin/end appearance transitions for <UINavigationController: 0x79a868c0>.

I was experiencing the same issue, which was a strange side effect of having no network connectivity in the simulator. I reset the content and settings on the simulator which at least temporarily 'resolved' the issue.

This can happen for a few different reasons. Most of the time it is because you are animating 2 things at the same time. I have seen this happen when calling popToViewControllerAnimated: twice with both calls passing in YES. Another time this will occur is when you try to present a view controller from the view controller.

Thanks Chris, I believe my problem is related with presenting a view controller from the view controller. Is there any way to solve this problem?

Chris! I'm having the same problem with my code. Is there any thing you could do to help me?

'''ObjectiveC

-(void)viewDidLoad { [super viewDidLoad];

self.title = @"#PhotoBomb";

[self.collectionView registerClass:[THPhotoCell class] forCellWithReuseIdentifier:@"photo"];
self.collectionView.backgroundColor = [UIColor whiteColor];

NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
self.accessToken = [userDefaults objectForKey:@"accessToken"];

if (self.accessToken == nil) {

    [SimpleAuth authorize:@"instagram" completion:^(NSDictionary *responseObject, NSError *error) {
        NSString *accessToken = responseObject[@"credintials"][@"token"];
        [userDefaults setObject:accessToken forKey:@"accessToken"];
        [userDefaults synchronize];
    }];

} else {
    NSURLSession *session = [NSURLSession sharedSession];
    NSString *urlString = [[NSString alloc] initWithFormat:@"https://api.instagram.com/v1/tags/photobomb/media/recent?access_token=%@",self.accessToken];
    NSURL *url = [[NSURL alloc] initWithString:urlString];
    NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url];
    NSURLSessionDownloadTask *task = [session downloadTaskWithRequest:request completionHandler:^(NSURL *location, NSURLResponse *response, NSError *error) {
            NSString *text = [[NSString alloc]initWithContentsOfURL:location encoding:NSUTF8StringEncoding error:nil];
            NSLog(@"text: %@", text);
    }];

    [task resume];
}

}

'''

Moving the code to viewDidAppear puts the modal view animation into a continuous loop. The simulator presents the modal view and then dismisses it over and over.

Which do you think would be the best implement in this scenario and how would you do so? I'm only half a year into coding so I'm pretty new to this. Thank you so much for all your help!

I have a hacky solution to resolve this issue:

set a global: BOOL firstLoad;

in viewDidLoad: firstLoad = YES;

move the entire oAuth code to viewDidAppear and put int a if(firstLoad) { //oauth code}. after it is complete set firstLoad = NO;

This will ensure that the it executes when the navigation controller has finished animating, but only executes the oAuth stuff once