I just got done upgrading everything for iOS 8.0 and noticed that everywhere DisplayActionSheet is used it causes a System.InvalidOperationException:
"The underlying Task is already in one of the three final states: RanToCompletion, Faulted, or Canceled."
It does not happen for any of the Simulator iPhone options.
I am seeing the same behavior with this project:
https://github.com/xamarin/xamarin-forms-samples/tree/master/WorkingWithPopups
Any help is greatly appreciated!