Mixing UIScrollView with gesture recognizers and UIView Transition animations causes rare crashes
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I've run into a problem when using UIScrollViews and UISwipeGestureRecognizers.

The way I've got my app set up, is that I have a master view with a subview called _ContentView with swipe gesture recognizers attached to it, and when swipe is detected, i change the subview using:

        //remove gesture recognizers from old content
    [_ContentView removeGestureRecognizer:_UpSwipeRecognizer];
    [_ContentView removeGestureRecognizer:_DownSwipeRecognizer];
    
    //perform change
    [UIView transitionFromView: _ContentView
                        toView: newView
                      duration: TRANSITION_ANIMATION_TIME
                       options: animation
                    completion: ^(BOOL finished) {
                        _ContentView = newView;
                        [_ContentView addGestureRecognizer:_UpSwipeRecognizer];
                        [_ContentView addGestureRecognizer:_DownSwipeRecognizer];
                        }];

So after that I have new _Contentview. All works fine, until I use one of the _contentViews has a UIScrollView as subview.

Not often (more often on older=slower devices) the app will crash because of 

    *** -[UIScrollView _canScrollX]: message sent to deallocated instance 0xf9d7380

meaning that after the transition is made, the scrollview still receives some messages from i guess the internal uiscrollview gesture recognizers.

I've tried disabling user interaction before beginning the transition, but that does not help.

Is there a way to cancel all touches to the scrollview after my gesture recognizer fires?
Or do I need to hold on to the scrollview long enough, let it run it's actions and release it later? - seems like a horrible solution.

I'd welcome some advice on hot to proceed with this one.

cheers.

