[Ryan Moore]

Yup, it’s PNGs!

I had been using them for a while to create 2.35 crop bars. Something I changed suddenly made this bug appear. It seems to have something to with accidentally having two PNGs overlap each other, or else having them on the topmost video layer. Final Cut would consistently crash and give a useless error report, except once when it finished but rendered a few seconds of the movie with a weird “Predator” infrared type effect.

This is a pretty major bug and I would try reporting it if I thought Apple would ever in a million years listen. We can see their typical attitude right here in this thread, attributing it to random things like “your system” or “prefs” rather than admitting a fairly substantial flaw in Final Cut. Oh well.