After selecting a different window decoration and clicking apply then systemsettings gets hung and has to be closed out. .session-errors show file:///usr/share/kwin/kcm_kwindecoration/Previews.qml:37: ReferenceError: savedIndex is not defined file:///usr/share/kwin/kcm_kwindecoration/Buttons.qml:149: ReferenceError: iconLabel is not defined Qt 5.9.0 Plasma 5.10.1 Frameworks 5.34.0 kernel 4.11.3
To reproduce click on the "all settings" button after changing window decorations.
Please mark invalid. I created a new user and it works properly under the new user some I have something odd with my existing user.