I was just trying to create a new project with the latest templates I found on the GitHub, but was getting this warning:
Warning: Attempt to present <CustomAlertController: 0x7b287800> on <CoronaViewController:
0x7b27ec00> whose view is not in the window hierarchy!
and the coronaView would not display. I changed the viewDidLoad() override func to viewDisAppear( animated: Bool ) and that solved the issue for me.