enter image description here

When I try to lock the screen it just freezes. It is not possible to log on again. It used to work perfectly and suddenly it does not. However, I am not aware of any recent updates or similar.

I would try to reinstall the component that is responsible for locking the screen. Which one would that be?

  • @PRATAP yes, but with the same buggy behavior – Christian Jan 25 '19 at 15:15
  • I exactly followed these steps and it solved the problem. – Christian Jan 25 '19 at 15:35
  • Unfortunately, the problem appeared again. – Christian Jan 27 '19 at 20:53
  • Seems like I have the same problem. Ctrl-Alt-F1 helps temporarily, as it allows me to log in back. But I'd like a proper fix. Also applications dock (on the left) breaks at the same time. Unfortunately, I haven't noticed which particular update brought this behavior, but it was something from last month. And I have it on two different machines, both ubuntu 18.04. – Imaskar Jan 31 '19 at 8:43
  • Update the system with sudo apt update && sudo apt upgrade or you can do fresh installation of 18.04.2. – d a i s y Jan 31 '19 at 9:45

You can track the bug here. Dash to Dock Gnome extension is causing it.

Upgrading packages helped for me.

Also known temporary workarounds:

  1. Ctrl+Alt+F1 after locking to repaint screen.
  2. Win+L twice to hide screen content (the dock will still be visible, though)
  3. after logging back Alt+F2, type r, enter. To reset Gnome and fix broken dock.
  • 2
    It seems more likely to be correct but not a proper answer and seems as comment. Please provide a detail answer with describing which package to upgrade and how to otherwise it will be deleted. – d a i s y Jan 31 '19 at 9:57
  • 1
    The bug was in dash-to-dock. I don't know which package contains it, probably gnome-software. Just update all packages. Deleting the only answer is surely useful thing to do, go on. – Imaskar Jan 31 '19 at 12:08
  • I realized that the upgrade fixed almost the problem, but if the laptop is docked I still have it. – Natim Feb 1 '19 at 8:44
  • Trying to upgrade to linux-headers-4.15.0-45-generic – Natim Feb 1 '19 at 8:45
  • Upgrading kernel won't help. Try installing latest dash to dock or disable it completely. Also note, that ubuntu dock is a derivative of dash to dock, so take a look at it, if it is enabled in your system (it is optional). – Imaskar Feb 1 '19 at 9:11

Might be related to this bug: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1656658

I've been getting a lot of screen hangs.

try opening a terminal and enter $dmesg -w

This will show you the last error... also consider getting your sys info with $inxi -Fxz

good luck!

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.