I'd probably do the same.  Probably....   But if you're correct in your theory about linux-firmware package being split into sub-package (I agree, that would be VERY high on my list, as it seems to provide a plausible explanation across all the theories posited so far), you're in a smaller subgroup than Arch users, who use LXQT, with LightDM (SDDM is the recommended DM, BTW).  If it's a firmware package, your old Toshiba may be using a firmware that very few users have installed.  MAYBE....   I'll wish you good luck getting it solved.  Stuff like this would just agitate my OCD to the point of "no rest until resolution".  At least your system is fully usable until a solution is revealed.  That's a small consolation to the OCD, but it IS a consolation.  LOL!

I tried to install wmpdart and can not get any sound out of it.  I installed mpd and think I have it configured right. Used systemd as per the wiki. The wmpdart dock app appeaser but does nothing. Am a tad stumped as to why ?   Any ideas folks ? 🤔

Mozilla sent Firefox Version 149.0.1 to the Release Channel.   Fixed Fixed text contrast issues in the sidebar with some dark themes. (Bug 1971487) Fixed a startup crash experienced by some users caused by DLL injection. (Bug 1973947) Update: To get the update now, select "Help" from the Firefox menu, then pick "About Firefox".  Mac users need to select "About Firefox" from the Firefox menu.  For non-English versions, Fully Localized Versions are available for download.   Release Notes

Yes I already tried a reinstall of LXQt and I'm sure it's OK on its own because I can launch it without the DM. The latest update to Arch split the linux-firmware package into several sub-packages. I don't know if that introduced a regression or not. Or maybe one of the video packages could be faulty. I haven't tried SLIM but honestly I am inclined to wait for a few updates before I try anything else. Right now this is on the oldest and most useless laptop I have, and it still works fine if I just log in in a TTY and then start the GUI with startx in the .xinitrc I'll also follow the discussion in the Arch Linux forum. I can't be the only user of LXQt in Arch with LightDM. Thanks for the suggestions.

conclusion....this is an Arch issue!   More specifically, an Xorg or LightDM or LXQT issue within Arch, but localized to Arch.  I'm thinking that pacman either sync'd a corrupted package (not likely), or deleted a package during sync (more likely), or the package got corrupted (most likely).  Have you tried re-installing LXQT?  Maybe even forced installation of missing packages with -f flag (I'm using Debian convention....not sure what the Arch equivalent would be?).   We've also established that LightDM and SDDM (the recommended DM for LXQT) both provide the same error.  What about an older "generic" DM like SLIM?