Swift UIAlertController -> ActionSheet iPad iOS8 Crashes

The error message is telling you that you need to give the alert controller’s popoverPresentationController a location so that it can position itself properly. This is easy to do — just check to see if there’s a popover controller and add the sender as the source.

If your button is a UIBarButtonItem:

if let popoverController = alertController.popoverPresentationController {
    popoverController.barButtonItem = sender
}
self.presentViewController(alertController, animated: true, completion: nil)

Otherwise:

if let popoverController = alertController.popoverPresentationController {
    popoverController.sourceView = sender
    popoverController.sourceRect = sender.bounds
}
self.presentViewController(alertController, animated: true, completion: nil)