Created attachment 112839 [details] demonstration open system settings, click "Configure" button on top, select "icon view" and click "Ok" button open "workspace theme", switch between the sections available on the left side Watch my screencast please. Already reported in Arch tracker https://bugs.archlinux.org/task/58704 "No, this is not a packaging issue. The original upstream report was, but it has now become a messy mixture of unrelated issues. The "Error loading plugin" message is harmless and has been there forever. The actual error here is file:///usr/share/kpackage/kcms/kcm_lookandfeel/contents/ui/main.qml:198:26: Unable to assign [undefined] to bool file:///usr/share/kpackage/kcms/kcm_splashscreen/contents/ui/main.qml:41: Error: Cannot assign [undefined] to int" Currently I use plasma 5.13 beta + qt 5.11 rc2 + frameworks 5.46, but plasma 5.12.5 + qt 5.10.1 + frameworks 5.46 had the same problem.
For reference, the misleading "Error loading plugin" message is due to https://bugs.kde.org/show_bug.cgi?id=348798 and is unrelated to this issue
And actually, the QML errors are also unrelated. The sidebar mode throws the same QML errors and this bug is not reproducible there.
I can't reproduce this problem anymore on Arch Linux running plasma 5.13.
Yes, this is fixed in kdeclarative 5.47 by https://cgit.kde.org/kdeclarative.git/commit/?id=5ec7d0d83d0fcee619406b42bf0a53d4298189f9
*** Bug 397905 has been marked as a duplicate of this bug. ***