I had it crash initially after pressing START (loading and pressing A was fine), but after changing the second layout to switch on the BACK button instead of START it no longer crashes. Is that the same for you?
If so, then it's mainly because the check for START being pressed is happening so fast it probably triggers on both sheets and that causes a freeze in game logic.
Changing layouts quickly/pressing both still causes the crash, so I would put a timer variable in that gets reset every time the layout changes and prevents transitioning between layouts for at least a second or two after the new layout has begun running.
Hope that helps!