AME gets stuck when encoding an mp4 file

Hi, I have an unusually long video (8h) which exports into an approx 110 gb file.

When I export with AME into an mp4 the procedure freezes when encoding is practically finished (estimated time comes down to 0 and elapsed time freezes too).

I read at that stage the process called muxing takes place and it might take some time considering the size of the file. Strangely, however, the processor's capacity  is hardly used at that time. Encoding took about 6 hours and I have allowed more than that for muxing (which i cannot monitor) and there seems to be no progress. To make sure I used the option not to export audio (as the movie is silent anyway) but it has not changed anything.

I have successfully exported the movie when i set multiplexing to none and i have acquired a m4v file. Unfortunately that file is not playable in any software I have, including VLC, other players give me errror code 0xc00d36c4. The file however is playable when i import it back into the Adobe Premier Pro.

Is there anything else I can try?