Lightdm doesn't start if /usr/share/lightdm/remote-sessions is missing

[PeterPall]

Symptoms:
 - Screen goes black after booting and showing the plymouth ubuntu logo and stays black or
 - screen keeps switching back and forth between text and greaphics mode instead of showing the login screen

How to trigger:
 - Take a system that has lightdm installed
 - Install gdm
 - select "gdm" as the new login manager
 - purge lightdm
 - restart the system
 - install lightdm-gtk-greeter (which automatically installs lightdm again)
 - select "lightdm" as login manager
 - restart the system

Somehow the directories /usr/share/lightdm/remote-sessions and its parent directory /usr/share/lightdm get lost during this sequence and aren't created anew when lightdm is installed.

How to recover in the case the problem has been triggered accidentally:
 - start the system in recovery mode
 - grab a root console
 - create the missing directory by typing
mkdir -p /usr/share/lightdm/remote-sessions

Did manage to trigger this problem twice on my computer since I switched to the developer's version of quantal (64 Bit).

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: lightdm 1.4.0-0ubuntu1
Uname: Linux 3.6.0-999-generic x86_64
ApportVersion: 2.6.1-0ubuntu1
Architecture: amd64
Date: Mon Oct 8 22:46:00 2012
EcryptfsInUse: Yes
SourcePackage: lightdm
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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

[ruff (rufferson)]

I've purged mythbuntu-lightdm-theme and lightdm fails to start now with this message.
The directory /usr/share/lightdm/ doesn't exist at all btw, only lightdm-gtk-greeter.

[ruff (rufferson)]

My apologies, it appears the log is two days old and lightdm simply failed to start due to wiped out greeter-session from config.

[ruff (rufferson)]

It still logs that message about missing dir but starts without problem.

[Robert Ancell (robert-ancell)]

Closing assumed fixed.