Your log shows that you are running /usr/share/lightdmxrandr.sh as a setup script for the X sever and this is failing. Can you disable this in /etc/lightdm/lightdm.conf and see if this fixes the problem?
** Changed in: lightdm Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-ati in Ubuntu. https://bugs.launchpad.net/bugs/1127767 Title: Lightdm service does not run with fglrx installed To manage notifications about this bug go to: https://bugs.launchpad.net/fglrx/+bug/1127767/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp