"Application tried to present modally an active controller"?

The same problem error happened to me when I tried to present a child view controller instead of its UINavigationViewController parent

I have the same problem. I try to present view controller just after dismissing.

[self dismissModalViewControllerAnimated:YES];

When I try to do it without animation it works perfectly so the problem is that controller is still alive. I think that the best solution is to use dismissViewControllerAnimated:completion: for iOS5

Assume you have three view controllers instantiated like so:

UIViewController* vc1 = [[UIViewController alloc] init];
UIViewController* vc2 = [[UIViewController alloc] init];
UIViewController* vc3 = [[UIViewController alloc] init];

You have added them to a tab bar like this:

UITabBarController* tabBarController = [[UITabBarController alloc] init];
[tabBarController setViewControllers:[NSArray arrayWithObjects:vc1, vc2, vc3, nil]];

Now you are trying to do something like this:

[tabBarController presentModalViewController:vc3];

This will give you an error because that Tab Bar Controller has a death grip on the view controller that you gave it. You can either not add it to the array of view controllers on the tab bar, or you can not present it modally.

Apple expects you to treat their UI elements in a certain way. This is probably buried in the Human Interface Guidelines somewhere as a "don't do this because we aren't expecting you to ever want to do this".

In my case i was trying to present the viewController (i have the reference of the viewController in the TabBarViewController) from different view controllers and it was crashing with the above message. In that case to avoid presenting you can use

viewController.isBeingPresented

!viewController.isBeingPresented {
          // Present your ViewController only if its not present to the user currently.
}

Might help someone.