"changing property masksToBounds in transform-only layer, will have no effect" in Xcode 7
In order to get rid of this error un check clip to bounds option and put scale to fill to view to all view,UIStackView you have used in your project.
This is a bug in iOS, and still exists in the latest version, iOS 9.1. If you're reading this, please do us all a favor and file a bug report with Apple.
You may duplicate my radar (id: 23666339), which can be viewed on Open Radar here: https://openradar.appspot.com/23666339
The bug causes the keyboard to take forever to appear, and exists only on iPad as well as the iPad simulators.
UPDATE: This issue has been resolved as of iOS 9.2 (13C75).
It could happen because you changed drawing attribute of the StackView:
when I set clips to bounds to true I get this warning