Long Multiframe Render stops showing time to completion

Using MFR produces a ton of temp files and cache data and you likely simply run out of disk space in the sense that you are exceeding some limit. As a start, render without MFR. Other than that the usual culprits could be issues with hardware acceleration requiring to switch to software only modes, full caches needing a cleanout and so on. Agree with Rick, though. If you're using AE for long form editing, you're using it wrong and should consider switching to Premiere for such stuff.

Mylenium

If there are cuts in your hour-long video, you probably used After Effects as a video editing application. AE was never designed to do that. You should be editing in Premiere Pro or another NLE, and you should be creating effects shots and animations in After Effects, rendering them one at a time, then finalizing the edit, the sound mix, and the color correction in Premiere Pro (or your favorite editing application). Even inside the editing app, long-form videos should not have everything in a single sequence (timeline).  Feature films are assembled by cutting scenes into separate sequences, then adding those sequences to a new sequence that contains the whole movie. This keeps the pieces manageable and saves time in the long run.

Long renders can eat up system resources, and the reduction is cumulative. That makes long renders much more susceptible to hangups and crashes. Whenever I have a render that takes more than a couple of seconds a frame, I render an image sequence. If I get a render failure, I can pick up the render from the last good frame instead of doing the whole thing over again. You cannot usually do that with a failed movie render. I am just guessing that the info calculations may just be running out of system resources on some renders.

I don't know if this helps.