After running `sudo nala full-upgrade` and rebooting, plasmashell was crashing in a loop. I tried booting with the old kernel, cleaning the cache, reinstalling plasmashell, reinstalling the widgets, all without success. This article worked!
KDE Plasma crashes after system update on Kubuntu 26.04: fontconfig race condition fix Mišo Oroz Mišo Oroz Mišo Oroz Follow for Zerolock Sep 23
We haven't written up this one. Dev.to has the full story — the link below goes straight to it.