ERROR:(null) is not a valid containment controller key path?

Question

I'm trying to present a navigation controller as a modal and I'm getting this warning:

ERROR:(null) is not a valid containment controller key path

Does anyone know what am I doing wrong? I just connected a segue from a button in another navigation controller to the designated navigation controller and it won't work and I get this warning.

Answer 1

This looks a bug in XCode note the sample "Utility App" displays this warning as well, but functions as expected.

Answer 2

Looks like you're passing a value which is actually holding nothing at all, to your navigation controller. I'd use NSLog to check the contents of the value being passed to the controller, and find out why it's null.