The modalPresentationStyle of a UIAlertController with this style is
UIModalPresentationPopover. You must provide location information for
this popover through the alert controller's
popoverPresentationController. You must provide either a sourceView and
sourceRect or a barButtonItem. If this information is not known when you
present the alert controller, you may provide it in the
UIPopoverPresentationControllerDelegate method
-prepareForPopoverPresentation.
Crash was caused by the following error: