MDDN 243 - Stencyl Crash

I've come across a problem with my stencyl file. Whenever I play the game, it starts perfectly fine and the music runs and all the imagery comes up. But then! as soon as you press a button to move the character from side to side, the flash player freezes, not responds, and crashes. I haven't changed anything from the time that it worked to now, and i have no idea how to fix this...
I severely hope that the code that is present in the prototype and the behaviours and animations that are present are enough for the teachers to mark, because i have no idea why this is happening!!