Kded5 dies immediately after I log into Plasma

As soon as I log into KDE Plasma, the KDE crash handler pops up, saying: “We are sorry, kded5 closed unexpectedly. You cannot report this error, because kded5 does not provide a bug reporting address.” Then there’s a line saying that executable kded5 has segfaulted.

There are lots of minor consequences: Ctrl+Alt+T doesn’t bring up a Konsole window; window decorations are wrong; the keyboard repeat rate I’ve configured isn’t applied; sound is unreliable; and probably more.

This started happening a few days ago, after a big ‘sudo dnf update’. It seems to be the same as this: https://bugs.kde.org/show_bug.cgi?id=466567.

At the moment, I’ve asked my wife not to apply security updates to her laptop in case her desktop breaks in the same way. That’s obviously not good.

Has anyone found a work-around?

I’ve found a work-around, of sorts. It involves changing window decorations from Plastik to Translucent — not easy when systemsettings keeps crashing. I’ve added more details to the kde.org bug report.