No login screen after updating from Ubuntu 15.04 to 15.10

[Héctor Velarde]

I tried to upgraded my computer from Ubuntu 15.04 to 15.10; everything ran smoothly but when I rebooted it, the login screen was missing and now I'm not being able to use it.

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: gnome-shell 3.16.4-0ubuntu1
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-16-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.19.1-0ubuntu3
Architecture: amd64
Date: Mon Oct 26 17:52:29 2015
DisplayManager: gdm
GsettingsChanges:
 b'org.gnome.desktop.interface' b'gtk-im-module' b"'gtk-im-context-simple'"
 b'org.gnome.desktop.interface' b'monospace-font-name' b"'Monospace 11'"
 b'org.gnome.desktop.interface' b'cursor-size' b'18'
 b'org.gnome.desktop.interface' b'clock-show-date' b'true'
InstallationDate: Installed on 2010-09-25 (1857 days ago)
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Beta amd64 (20100901.1)
SourcePackage: gnome-shell
UpgradeStatus: Upgraded to wily on 2015-10-25 (1 days ago)

[Launchpad Janitor (janitor)]

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

[Michael Hrivnak (mhrivnak)]

This is my .xsession-errors, which seems to be full of error messages.

I also upgraded from 15.04 to 15.10 and have the same problem. I have reinstalled nvidia-340 with no change. I can't start gdm or lightdm. I tried purging and reinstalling gdm, but that didn't help. Like the reporter, I can login from tty1 or via SSH.

[Michael Hrivnak (mhrivnak)]

My apologies! Apparently that .xsession-errors file is from a week ago, when I still had a working install of 15.04, and its calamity of scary error messages is... normal?

I deleted it, rebooted, and I'm not seeing it get recreated.

I will try to attach other relevant data.

[Michael Hrivnak (mhrivnak)]

Here is the output of "sudo journalctl -b". There are some exciting gdm-related error messages at Oct 28 21:34:34 that look suspicious.

[Brian O'Keefe (okeefe)]

I can also login with TTY and then "startx".