After viewing the details of an image from a TWTRTimelineViewController on iPad, tapping the action button in the navigation bar crashes the app:
2016-01-11 15:58:04.646 Express[35870:16474153] *** Terminating app due to uncaught exception ‘NSGenericException’, reason: ‘UIPopoverPresentationController (<_UIAlertControllerActionSheetRegularPresentationController: 0x7fc70335d5f0>) should have a non-nil sourceView or barButtonItem set before the presentation occurs.’
This appears to be related to this previously-reported issue, which @stevenhepting said was fixed back in July 2015. Edit: also reported here a few weeks ago.