Cannot update software - always asks "choose a provider for qt6-multimedia-ffmpeg", then fails

Looks fine.

Still somehow was not included above …

cd ~/.config && for j in plasma*; do mv -- "$j" "${j%}.bak"; done && mv Trolltech.conf Trolltech.conf.bak && rm -rf ~/.cache/* && kbuildsycoca6 --noincremental && cd ~ && echo -e "\nFinished Clearing Plasma Settings and User Cache.\n\nPlease Reboot.\n"

Its the one-line equivalent of the multiple commands usually employed after big plasma upgrades … removing cache and configs.

One of the other mods here also created a script

This should have been done earlier when setting defaults back to breeze.

And will reset desktop settings.

If you havent noticed any weird issues it may be skippable I guess, but previous experience was that every system undergoing upgrade from plasma5 > plasma6 would want to run them.

(ex: Problems after Plasma 6 update - #2 by cscs)

And the archwiki section with the separate minimal steps for reference

https://wiki.archlinux.org/title/KDE#Plasma_desktop_behaves_strangely