I sort of have the same problem on my iMac. I will be using it and all of a sudden it will quit. I noticed this would normally be if I leave for a while and the computer goes to sleep. So I just make it a habit to shut down when I'm done or restart if it's been asleep for a while. Haven't had any problems if the computer doesn't sleep. Just my experience. I couldn't get any editing done without the damn thing. Best tool I have.