lightdm from Debian 8, oldstable, did not function properly in the Debian 9 environment. Instead of drawing one blank screen like when connecting to the Debian 9 lightdm, XWin, when connecting to the Debian 8 lightdm, would continually redraw its window decorations but still not draw any login dialog. Certainly not useful. Issue Lubuntu 13.10 [140103] Whist the display manager greeter is displayed, Ctl-Alt-F7 takes us back to an unlocked desktop! This can be quite a security issue until fixed. See a work-around below. A similar command will also lock the screen and switch to the display manager's login screen. lightdm-webkit-theme-archlinux doesn't even depend on this but lightdm-webkit2-greeter There is a reason why you should check what you update especially from AUR. Anybody is more than welcome to send logs, I am still following and troubleshooting this issue in between my university studies and other personal life even though pepper_chico is ...