Error - custom transitions require both a fromViewController and toViewController

Question

I am attempting to dismiss one view controller from the presenting view controller and the upon completion handler of the dismiss, attempting to pop the presenting view controller from the navigation stack.

I receive this error:

custom transitions require both a fromViewController and toViewController!

What does this error mean?

If I attempt to call both dismiss of the presented view controller and pop of the navigation controller's current view controller, I receive a different error message:

[_UIViewControllerOneToOneTransitionContext _setPresentationStyle:]: message sent to deallocated instance