Ubuntu – Ubuntu 17.10 with LXDE locking leads to black/blank screen


I recently upgraded to Ubuntu 17.10. As my laptop is rather on the weak side (performance wise), I grew quite uncomfortable with the new desktop as everything seemed to take longer, the laptop being slower overall.

So, I installed LXDE, lubuntu-session packages, etc., to make a transition to the more lightweight LX desktop environment. I am super happy about it, as the system now feels super fast and responsive.

One issue remains: If my session gets locked (by timeout, laptop lid close, or manual lock) I end up with a black and empty screen. Not even a mouse pointer, not responding to any clicks or simple key presses. The only remedy I found was killing/rebooting the entire machine.
After some playing around, I found that Ctrl+Alt+F1 takes me back to the login screen.

I tried to google for this problem, but didn't find any help: Several similar problems were discussed, like having no login screen right after boot (which is not my problem), of another solution talking about "Light Locker Settings" and turning off/on some stuff – but I don't seem to have this menu…

I do not really understand what's going on, and why I seem to end up at the wrong Ctrl-Alt-F* interface.

For me it's only a thing of minor to medium importance, as I found a way to work around it. But, of course, I would be glad if someone could point me to a clean solution.

(A solution is great, but if you could elaborate your answer a bit, I would be very grateful, as I'd really like to learn more about the inner workings of my system.)

Best Answer

  • Press Ctrl-Alt-F1 to go to a virtual terminal, and log in. Issue this command:

    ps ax | grep lock

    If you see light-locker running, kill it

    killall light-locker

    Return to your gui by pressing Ctrl-Alt-F7. Hopefully it is unlocked now.