Tried the viewer again just now. Started with a random film I made a few weeks ago about 3 minutes long. That film ran fine through to the finish. Then I tried one I made in FSO the other night. It made it about a minute and a half in before crashing. Better than yesterday's attempt.
Here's the difference: I never changed any settings. When the film finished loading the time counter still flickered but it stopped once the film started running. Usually I'll check the box for use recorded view (or whatever it's called) and maybe external view, but this time I just let it sit in the internal straight ahead cockpit view.