Start-up error.
 

I'm on a Mac and whenever I try to go on OOTP 19, this happens.

"OOTP found that the crashed_on_startup flag is set. Obviously the game crashed when you started it last time. OOTP will reset the graphics settings to default values. You can set them back later in the Game Preferences dialog."

I'm on Steam, but it doesn't look like a Steam problem. my game didn't crash last used and this just happened yesterday. How do I fix it?