Ubuntu: Xubuntu frozen when locking screen


Since I upgraded to Xubuntu 16.04 every time I lock the screen I get a black screen (with a white dash cursor in the top left corner) and there's nothing I can do to unlock it (I've tried Ctrl-Alt-F1 and Ctrl-Alt-F7 but nothing happens), except hard reboot.

Do you have suggestions to solve (or debug) this issue ?


To debug

  • Install accountsservice and xserver-xephyr, where
    • accountsservice for Enhanced user accounts handling
    • xserver-xephyr for LightDM test mode

Then run LightDM as an X application for debugging: $ lightdm --test-mode --debug

  • LightDM's log file is /var/log/lightdm/lightdm.log, you will need root privilege to view it.
  • Or see output of dmesg with sudo dmesg.

List of workaround methods

  • Try to suspend and resume again

Press CtrlAltF1, then login and type systemctl suspend. Press power button to resume and switch to tty7 by CtrlAltF7. In my case, I did 2 times to escape the blank screen.

sudo mv -v -i /etc/xdg/autostart/at-spi-dbus-bus.desktop /etc/xdg/autostart/at-spi-dbus-bus.desktop.disabled

  • Replace light-locker with xscreensaver, then reboot.



Well, sudo apt-get install --reinstall xscreensaver may do the work for you. If this doesn't work try sudo apt-get purge --auto-remove xscreensaver && sudo apt-get install xscreensaver.

Note:If u also have question or solution just comment us below or mail us on toontricks1994@gmail.com
Next Post »