After upgrading from 13.04 to 13.10 I cannot get any image to display on the login screen, why?

I can login in without any issue & can display any image as my wallpaper. But the default image does not display. I've even tried using ubuntu-tweak to change the image, but all that is displayed is a plain black screen, with the user list.

I've tried looking at dmesg, Xorg.0.log, syslog, user.log, but can find no indication as to what is the cause. So can anyone help me? Thanks.

To change the login screen background of the lighdm login manager:

1. First backup the configuration file:

   sudo cp /etc/lightdm/lightdm-gtk-greeter.conf /etc/lightdm/lightdm-gtk-greeter.conf.old
   

2. Then edit it, changing background=CURRENT-IMAGE.jpg to background=LOCATION-OF-WANTED-BACKGROUND-IMAGE.jpg

   sudo gedit /etc/lightdm/lightdm-gtk-greeter.conf
   

3. Then test it, by running:

   sudo lightdm --test-mode
   

Give this a try...

Add the user localuser:lightdm to the access control list.

• sudo xhost +SI:localuser:lightdm

Now using su, change/log-in as the user lightdm;

• sudo su lightdm -s /bin/bash

Now to turn off the grid of white dots use:

• gsettings set com.canonical.unity-greeter draw-grid false

To set a unity-greeter default background:

• gsettings set com.canonical.unity-greeter background [YOUR_BACKGROUND_IMAGE], YOUR_BACKGROUND_IMAGE could be in your Pictures folder or /usr/share/backgrounds, where I keep it, or from wherever the system can access. Make sure the image file has read permissions set. e.g. gsettings set com.canonical.unity-greeter /usr/share/backgrounds/myWelcomeScreen.jgp And then chmod 444 /usr/share/backgrounds/myWelcomeScreen.jgp to make it readable to all users.

To set your desktop wallpaper for greeter screen:

• gsettings set com.canonical.unity-greeter draw-user-backgrounds true

Next time the greeter screen should appear the way you want it to.