Zoom: How to recover non-converted .zoom files when they refuse to convert? (Disappearing Conversion Window)

This problem with Zoom recordings was really frustrating to figure out! First, I had .zoom files from a meeting recording, that had failed to convert to video. Then, every method I tried to get them to convert, didn’t work. The conversion screen would disappear every time, or get stuck at “0%” forever. After lots of trial and error…here’s the fix! Please note: First, I consider this an ADVANCED fix and cannot provide support beyond the description here. You have been warned. Second, ...