I’m still somewhat “new” to Linux, but I’ve been running Neon off and on dual booting through grub for a couple years.
About a month ago I had a real struggle trying to install the most recent 5.27.9 system package (the one that was around 900mb in size). I posted details on reddit here, but the tldr is that the update seemed to remove Discover, and trying to fix it broke grub. I attempted to follow a couple guides to fix it, but I eventually ended up reinstalling from scratch, which fixed my boot issues.
I then reinstalled the updates, and this time had no issues with the process (it was extremely quick), but once again, after rebooting, Discover has vanished again (the shortcut to launch it from the system bar is greyed out, and when I try to launch it, I get a “Plasma Workspace: unknown application folder”, and I cannot find it from the system menu either, although I do have an option from the search to “Get Discover”, but clicking this doesn’t do anything.
I didn’t find any hits on the forum for “unknown application folder” relating to the disappearance of Discover, but there is a recent post that’s identical to my issue where the System settings have similarly stopped working.
When I google the error I’ve found a number of people recommending running pkcon updates (which is what I’d tried when I broke grub last time around), and when I try it again it completes successfully, but after a reboot the issue persists. There seem to be other people in my reddit post with identical issues, and I’ve tried the various fixes without any success.