Here we go! /usr/bin/xflock4 is a script expecting a value by xfconf-query -c xfce4-session -p /general/LockCommand which returns nothing on my machine. Apart from lightdm on my machine the packages slock and xlockmore are installed and before xflock4 stopped working, it seemingly used xlock -mode blank. After using xfconf-query to set the wanted value, xflock4 is working again. xfconf-query -c xfce4-session -p /general/LockCommand -s "xlock -mode blank" However, I'll rethink to use xflock4 by panel entries or scripts for openbox sessions. Maybe I chose xflock4 years back for portability among Xfce4 and openbox or other sessions. Actually I didn't start a Xfce4 session for years. Regards, Ralf
