Warning :-Presenting view controllers on detached view controllers is discouraged

To avoid getting the warning in a push navigation, you can directly use :

[self.view.window.rootViewController presentViewController:viewController animated:YES completion:nil];

And then in your modal view controller, when everything is finished, you can just call :

[self dismissViewControllerAnimated:YES completion:nil];

Wait for viewDidAppear():

This error can also arise if you are trying to present view controller before view actually did appear, for example presenting view in viewWillAppear() or earlier. Try to present another view after viewDidAppear() or inside of it.

The reason of this warning is i was presenting a view controller over a small view that is not full size view. Given below is the image of my project. where on click on four option above. User navigate to different childviewcontroller's view.(it works like tabViewcontroller). But the childviewcontroller contains view of small size. So if we present a view from childviewcontroller it gives this warning.

And to avoid this, you can present a view on childviewcontroller's parent

  [self.parentViewController presentViewController:viewController animated:YES completion:nil];