UIWindow endDisablingInterfaceAutorotationAnimated error appears in console when keyboard is dismissed interactively from collectionView in iOS9 only

I had the same problem on iOS9 but with a tableView. I implemented this along with self.tableView.keyboardDismissMode = .Interactive and it worked for me.

// Dismiss keyboard when scrolling
func scrollViewWillBeginDragging(scrollView: UIScrollView) {
    textView.resignFirstResponder()
}