#PROBLEM
Alec, I can't help you much without knowing how much hard disk space you
had free, what palette mode you were in, etc. My guess is that you were in
High Palette mode and ran out of disk space. It doesn't recover very
elegantly from that. High PMode makes a tga temp file for EACH FRAME. It
can use hundreds of megabytes for long flics.
Note that this flic is unusable and you're going to have to re-render. Try
Medium mode (or better yet, use Custom).
– G