Hello,
with the accompanying MRs
https://invent.kde.org/frameworks/plasma-framework/-/merge_requests/458 a few
plugin files got renamed
to ensure that their file name matches the plugin id. Please ensure that the
old plugins are deleted,
with kdesrc-build the directory is
~/kde/usr/lib/x86_64-linux-gnu/plugins/plasma/applets/.
After removing this dir, you should install plasma-workspace and optionally
kdeplasma-addons (if that is part of your build setup).
Users of package managers will not have any issue, because there old files are
deleted.
Regards
Alexander