I had been seeing a crash for the last few days, and hadn't figured it out. In my case the crash happens after a few seconds of the app being open. It doesn't matter what you do in those few seconds, the app will crash. Even if I let the app stay on the initial screen, where there is just a stop(); action, and no sounds or video going on, it will still crash.
Changing to using the release version of AIR 14 fixed the issue.
I'm happy to have seen this message come in!