After Effects suddenly "cannot parse file" in iff sequence

Hello!

I just rendered an .iff sequence in Maya, which I usually convert to .movs using After Effects. I have been doing this since as recently as four days ago, even with some of the exact same frames I tried to render today with no issues. However, now when I import the sequence, it will play a few times, then suddenly say it cannot parse the file, and then make the entire sequence unplayable. I renamed some of the files, which worked for a few minutes, only to start saying it couldn't parse the file again, and then corrupt the previously working frames.

I've been working on these frames for DAYS and now it looks like they'll be unusable. I haven't been doing anything differently, and I can't find an answer. Please help.