System settings is set to Icon View mode Clicking on items under Display and monitor closes System Settings Output in console is following: [anon@loonix ~]$ systemsettings5 wl_display@1: error 0: invalid object 99 [anon@loonix ~]$ systemsettings5 wl_display@1: error 0: invalid object 83 [anon@loonix ~]$ systemsettings5 wl_display@1: error 0: invalid object 81 [anon@loonix ~]$ systemsettings5 wl_display@1: error 0: invalid object 166 If System Settings is set to Sidebar View, Night Color, Gamma and Compositor do open up, with a delayed. Arch Linux Qt 5.10.1 Plasma 5.12.1
*** This bug has been marked as a duplicate of bug 389087 ***