I started seeing the problem only recently in two machines, one running 15.2 and the other 15.3 both running LXQt. I have the 15.2 machine in front of me having this problem. I have been capturing all journal messages during an attempt to launch YaST2 from the menu (journalctl -n) and see nothing written at all. The following is the output from running xdg-su. Maybe you see something unusual, but the part about User 1000 not owned by UID 0 is usual and also displays when I launch from a root console. # xdg-su -c "/sbin/yast2" QStandardPaths: runtime directory '/run/user/1000' is not owned by UID 0, but a directory permissions 0700 owned by UID 1000 GID 100 lxqt-sudo: Stripping child environment except for: DISPLAY, LANG, LANGUAGE, LC_ADDRESS, LC_ALL, LC_COLLATE, LC_CTYPE, LC_IDENTIFICATION, LC_MEASUREMENT, LC_MESSAGES, LC_MONETARY, LC_NAME, LC_NUMERIC, LC_PAPER, LC_TELEPHONE, LC_TIME, PATH, QT_PLATFORM_PLUGIN, QT_QPA_PLATFORMTHEME, WAYLAND_DISPLAY, XAUTHLOCALHOSTNAME, XAUTHORITY QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root' I can run same tests on the 15.3 machine tomorrow, but the observed behavior is identical to this 15.2 machine.