I've create three users on my computer (admin + standard users), and whenever I switch between users, my screen is turned off.
I have Ubuntu 16.10, and I switch users using the account menu on the top right corner.
I have two standard users who can login without a password. When I switch between them:
- Instantly and for a brief second I see the screen of the other user.
- The screen turns off (the LED indicator on the screen starts blinking).
- Now there are two options:
- The screen turns back on after a 1-3 seconds.
- The screen stays off until I move the mouse or click on a key, as if the computer is suspended.
When I switch to the administrative user, it is more complicated:
- The screen blinks for a second.
- I get the display manger where I need to enter my password.
- The administrative user might not be selected - I have to choose it again, and enter the password.
- I am logged in and see the screen for a brief second.
- The screen blinks.
- I see the display manager a second time. This time there isn't a list of users, only the administrative user. I enter the password again and log in without blinking.
- I see an error message:
Things that didn't work:
- I tried clicking on Ctrl+Alt+F7 to switch between TTY sessions. This sometimes works, but most of the times the screen still turns off.
- I tried
dm-tool switch-to-user username. This is the same as clicking the menu.
- I tried changing the power-saving options to disable suspend mode (screen never turns off when inactive). This had no effect.
- I tried switching the display manger to gdm3. This was terrible. The system wouldn't start and I had to use root console from grub to restore lightdm.
- I tried using an HDMI cable with my graphics card (Gigabyte RX 460 2G 1212Mhz WindForce2 OC), or a VGA cable to my motherboard (ASUS H110M-K DDR4). Both behave the same.
- I didn't try installing amdgpu-pro - it seems to support only 16.04, and isn't needed for 16.10 (which has built-in support).
Similar questions with no answers:
- Black sreen after switching user
- Blank screen after Switch User or Resume
- Ubuntu 16.04 LTS - Black screen after switching users
I will be switching users very often... How can I get this to work smoothly? Is there a log I should check?
I've found this on
ERROR: apport (pid 19659) Fri Dec 2 12:22:40 2016: called for pid 19445, signal 6, core limit 18446744073709551615
ERROR: apport (pid 19659) Fri Dec 2 12:22:40 2016: ignoring implausibly big core limit, treating as unlimited
ERROR: apport (pid 19659) Fri Dec 2 12:22:40 2016: executable: /usr/lib/xorg/Xorg (command line "/usr/lib/xorg/Xorg -core :3 -seat seat0 -auth /var/run/lightdm/root/:3 -nolisten tcp vt10 -novtswitch")
ERROR: apport (pid 19659) Fri Dec 2 12:22:40 2016: is_closing_session(): no DBUS_SESSION_BUS_ADDRESS in environment
ERROR: apport (pid 19659) Fri Dec 2 12:22:40 2016: this executable already crashed 2 times, ignoring
I think this is related because sometimes after switching users I see the error message, and sometimes hear the error message sound.