A few suggestions:
Go back to stack frame 9 and earlier, select the method name, google it. You're looking for posts from other people that have this same crash. There are some on the Apple forum. They seem to think it's an Apple bug.
You can set breakpoints on these methods even though they're not in your code. You might be able to figure out where in your code they get called.
If you are logging then add log statements to every screen in your app. Make a new release and look for the logs when it crashes to see which screen(s) it's on.
Good luck.