KDE tracker for this bug is here: https://bugs.kde.org/show_bug.cgi?id=338406
And another workaround has been suggested: https://forum.kde.org/viewtopic.php?f=225&t=126185&p=337354#p337354 "I've removed ~/.kde/share/config/*power* files and the battery-crirical-level-action came back! Best regards, Evgenii"
