Final Cut Pro - "Missing Plugin" Error Solved !?

I've seen this issue posted here and elsewhere for a couple years and I think I've solved it. The issue is this: you open your edit, and suddenly FCP says "Missing Plugin" even though you'r not even using special plugins. The app can also find the actual playable footage on the Finder, but can't relink it, and doesn't even think it's unlinked - so relinking does nothing.

The solution seems to be about Permissions. In your Mac's System Settings , go to "Privacy Security", then down to "Full Disk Access" and grant Final Cut Pro access. So far, this has solved my issue, but more testing needs to be done. Hope this helps anyone else with this issue!