I've just rendered an After Effects comp in .mov format, from two source .mov files, a mask and a null object. Trouble is, of the 1:30 or so total time of the video, around 1:00 is stuck on a single frame, after which the video resumes from the point where it *should* be. I've checked and double checked all the settings, and everything seems to be OK. This is the first time this has happened to me while using AE; I'm unsure what to do.
Does the composition look fine when you RAM preview?
As luck would have it, it now works. I just had to change the output format from QuickTime (.mov) to H.264@300kbps. Still haven't figured out the cause of the original issue; by the way, the RAM preview worked perfectly well, which is what surprised me most.