Kubuntu login screen not displayed

[Mike]

Since the upgrade to Xenial i have the problem that the login screen is not appearing. I only see a blank screen on both monitors.

I am able to switch to console and login. I also looked into the Xorg.0.log but there was no error, just nothing is shown. I tried restarting sddm and once had luck that it worked. Now even with restarting i can not get the login working.

Sometimes it shows the login screen but keyboard and mouse are not working there. CTRL+ALT+DEL restart still works.

I installed gnome now besides it and now have created the bug report from here. If i can provide additional information please let me know.

I did not have this problem in 15.10. It just started after the upgrade to 16.04.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: sddm 0.13.0-1ubuntu5
ProcVersionSignature: Ubuntu 4.4.0-15.31-generic 4.4.6
Uname: Linux 4.4.0-15-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_modeset nvidia
ApportVersion: 2.20-0ubuntu3
Architecture: amd64
CurrentDesktop: GNOME
Date: Mon Mar 28 22:56:35 2016
InstallationDate: Installed on 2016-03-26 (2 days ago)
InstallationMedia: Kubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160323)
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: sddm
UpgradeStatus: No upgrade log present (probably fresh install)

[Mike (mike-petersen-web)]

Sorry, made an error and created an additional bug instead of attaching the information here. I marked https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1563946 as duplicate. Here the comment:

Due to more testing i found out that the problem may not be related to sddm. Switching to gdm3 only worked sometimes.

I also found out that detaching one monitor and starting sddm works for me. I can connect the monitor again before loging in and everything is fine.

If i switch to gdm3 i not only need to stop/start the service. I also need to do a dpkg-reconfigure sddm and switch between sddm and gdm3 in order to have it working.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xserver-xorg 1:7.7+13ubuntu3
ProcVersionSignature: Ubuntu 4.4.0-15.31-generic 4.4.6
Uname: Linux 4.4.0-15-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_modeset nvidia
ApportVersion: 2.20-0ubuntu3
Architecture: amd64
CurrentDesktop: KDE
Date: Wed Mar 30 17:51:53 2016
InstallationDate: Installed on 2016-03-26 (4 days ago)
InstallationMedia: Kubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160323)
ProcEnviron:
 LANGUAGE=de
 TERM=xterm
 PATH=(custom, no user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Peter L Jones (peter-drealm)]

sddm does not start up at all but no error is reported anywhere - see systemctl checks log attached.

A rather clearer report is given running the command from the console:
root@nuc-peter:/var/log# /usr/bin/X -nolisten tcp -auth /var/run/sddm/{03a073a1-922f-4e49-b7c0-e86bf64358a5} -background none -noreset -displayfd 17 vt7
bash: /usr/bin/X: No such file or directory

And just to be certain:
root@nuc-peter:/var/log# ls -l /usr/bin/X
ls: cannot access '/usr/bin/X': No such file or directory

sddm itself is installed:
root@nuc-peter:/var/log# which sddm
/usr/bin/sddm

[Peter L Jones (peter-drealm)]

Well, that seems simple enough: xserver-xorg-core hadn't been installed. "apt install xserver-xorg-core" and then "systemctl start sddm" gets me a greeter.

[Mike (mike-petersen-web)]

@peter-drealm: Seems to be another problem for you. The package xserver-xorg-core is installed and /usr/bin/X is present.

Currently i am fixing it by removing the hdmi cable from the graphics card (one monitor) and the login screen apears. Before loging in i reconnect the monitor and it will be automatically used in KDE without setting it up again.

[Peter L Jones (peter-drealm)]

@mike-petersen-web - yes, in my case, it's definitely a dependency issue. I installed 16.04 server and then added Kubuntu Desktop. Whilst that installed sddm and its service, sddm didn't have any dependency on xserver-xorg-core, directly or indirectly (which it really should have, as it's an X display manager and runs /usr/bin/X :) ).

[Andrew McLeod (andrewclimbing)]

I have the same issue - upgraded from 15.10 to 16.04 (Kubuntu) and the login screen, after entering username/password, does nothing. Changing to the console and back seems to go straight to the desktop if you have left it long enough, which suggests the logging in is continuing and the greeter thing is just stuck or something?

I definitely have xserver-xorg-core installed.

[Peter Szabo (szpeter80)]

Upgraded from previous LTS, i have two monitors driven by the CPUs integrated graphic engine, the kernel autoloads i915 driver. SDDM does not start, it needs to be manually from a console prompt. Apart from this, all works OK after, as far as i can tell.

[Peter Szabo (szpeter80)]

Placing

service sddm start

into /etc/rc.local did a workaround. Also i think Bug #1431332 is related.

[Ernst Kloppenburg (ernst-kloppenburg)]

calling 'sudo dpkg-reconfigure sddm' seems to fix the problem (found the advice elsewhere and had success)
This should give a hint on what goes wrong during the upgrade, and how it could be fixed.

[dusoft (dusoft-staznosti)]

Reconfigure did not work for me.

See update:
https://github.com/sddm/sddm/issues/892#issuecomment-330970061

This bug is definitely related to the translations / user locale. Only English locale works correctly, all other locales will trigger this bug.

[dusoft (dusoft-staznosti)]

Sorry, wrong thread. Disregard last comment.