UIImagePickerController error: Snapshotting a view that has not been rendered results in an empty snapshot in iOS 7

The problem in iOS7 has to do with transitions. It seems that if a previous transition didn’t complete and you launch a new one, iOS7 messes the views, where iOS6 seems to manage it correctly.

You should initialize your Camera in your UIViewController, only after the view has Loaded and with a timeout:

- (void)viewDidAppear:(BOOL)animated 
{
    [super viewDidAppear:animated];
    //show camera...
    if (!hasLoadedCamera)
        [self performSelector:@selector(showcamera) withObject:nil afterDelay:0.3];
}

and here is the initialization code

- (void)showcamera {
    imagePicker = [[UIImagePickerController alloc] init];
    [imagePicker setDelegate:self];
    [imagePicker setSourceType:UIImagePickerControllerSourceTypeCamera];
    [imagePicker setAllowsEditing:YES];

    [self presentModalViewController:imagePicker animated:YES];
}