ReillyBrogan Cherry-picked a fix for Mesa that should fix issues with Flatpaks and Snaps not loading (or loading but throwing a graphics-related error). Please restart your system after applying this fix and things should work again on your next boot.
Apparently this fix destroyed Vivaldi. I wonder if any other Chromium-based browsers were affected. After quite a bit of fuss, I got LastPass installed and working on Firefox, so I was able to log on to the forum aagain.
I can live with Firefox for a while, but it would be great to know how to undo this last fix. In all my years here, I've never needed to know how to undo one of these.