wastelander
@ fungalnet, thank you so much for your detailed advice, you are right, I have seen that there are too many packages to downgrade and it would almost certainly be an useless work due to the sytemd dependecy of arch's pkgs. I would rather wait for the new package on the obarun repo =)
banned_9-26-2021
No it is only qt5-base that has the dependency and it is what is removed to remake the obarun package to replace it.
Meanwhile you can install openbox or jwm and xorg-xinit (if you don't have it already) and start a window manager instead of plasma and do your work. Your qt5 base software may still not work. If you need help with any of it let me/us know. Basically what is on live for jwm works for openbox (and other window managers), just replace on your ~/.xinitrc jwm at the bottom with exec openbox-session and then enter xinit or startx and you are on X. You may need to make sure xterm is installed as the default openbox right click menu points to xterm as terminal.
banned_9-26-2021
new qt5-base is in the repository, upgrade again.
Thank sleepless Eric
eric
:)
thanks at you to make report
wastelander
thank you all for the support! I used my installation media to get the live jwm desktop running, synced and updated my system and finally I had my desktop environment working :)