So I was trying to get Orcaslicer to run, but kept getting an error relating to the wrong version of glibc (2.38 required, 2.35 installed) when the helpful "would you like to upgrade to 24.04" requestor popped up again. the advice I had found online was that installing the later version of glibc under 22.04 was unwise, so I thought the upgrade might fix it.
Boy, bad move.
Now the system is completely borked. I have a completely blank desktop. The desktop directory is still there, and all the files are still in it, but the desktop is completely blank. There is a window switcher icon at the top left, what remains of the settings icon at the top right, an icon bar with what is left of the system apps on it at the bottom, and that's it. The app selector (right end of the icon bar) shows just about all the system apps as missing, including settings, software update etc. and a search for them comes up empty. The upgrade also removed Firefox, and now Firefox won't run (tried invoking it from a terminal). When I try to run firefox, I get a message saying that I have to use snap to install it. Snap reports that firefox is already installed. Snap refresh has no effect, apt upgrade has no effect, even with fix-dependencies.
Fortunately, my home directory is on a separate partition so it looks like that survived. Any advice before I blow the system away and fresh install 24.04 (or go find a better distro)?