This morning, my online Electrodynamics lecture ended in a slight disaster when the Zoom session crashed at the end. Since the lecture videos are an important part of the study material, I was worried that this crash had caused the loss of the recording.
Here is a basic description of where I was at:
Since the beefiness of the first file meant the data was actually residing on disk, the remaining task was thus to convert these files into the required mp4 video file.
The simplest solution of double-clicking-flles-to-convert obviously did not work: there is no free lunch. The next-simplest solution, as suggested at this Zoom support page, was to try to use the desktop client, and invoke the conversion from there. This did not work either: though the client started the conversion, the progress bar never got beyond 0% (even leaving it running for 4 hours).
Playing around, this workflow actually did the trick of recovering the original video:
If all goes well, Zoom will now start converting the video as expected, and you can process it further as per your own workflow. Precisely why this works must remain obscure to the sorry Open Source advocate that I am, since I can't look into the Zoom code... but a running meeting somehow magically manages to overcome and repair file corruption from a past, crashed meeting.