Ubuntu 14.04. Brightness & Lock settings are to turn off screen after 10 minutes and lock screen after 30 minutes. 50% of the time, when I wake my computer from suspend, the login field to enter my password is missing. Quite annoying. I have to CTRL + ALT + 3 to get to another.... shell? (still new-ish to Linux), log in and run:

sudo service lightdm restart

Where can I look to see what is going wrong. Is there a lightdm log of some kind?



The lightdm log can be viewed by running sudo less /var/log/lightdm/lightdm.log

The issue you're describing is a known bug. A few potential workarounds are shown in the comments on that ticket. One workaround is to drop into a terminal by pressing ctrl+alt+F1, logging in, and then running unity --replace. Other variations are shown in the bug comments.

  • Erm, your answer is correct, but sudo less /var/log/lightdm/lightdm.log would have been more informative to a user that is asking where the lightdm log is... ;-) (please edit and change and flesh it out a bit.
    – Fabby
    Jan 26 '15 at 21:41

This can be worked around without losing your session by:

  1. Switch to a tty (e.g. Ctrl+Alt+F1)
  2. Log in
  3. Run: sudo loginctl unlock-sessions
  4. Switch back to the Desktop: Ctrl+Alt+F7 (or F8).

From the bug report fori this issue and this answer to a similar question


I see in some cases it could be linked to the use of Nvidia drivers. See potential solution at https://ubuntuforums.org/showthread.php?t=2395562&highlight=suspend+resume+problems

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.