Indeed, this issue is caused by wrong permissions. in /var/lib/lightdm/x-0-greeter.log it said:
** (process:2235): WARNING **: Error reading existing Xauthority: Error opening file: Permission denied Error writing X authority: Error opening file '/var/lib/lightdm/.Xauthority': Permission denied And indeed, For some unkown reason, the files in /var/lib/ligthdm were owned by user speech-dispacher, group rtkit. After changing the owner of the files inside the directory to lightdm:lightdm, things work just fine. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/951555 Title: When using lightdm X starts in low-graphics-mode Status in “lightdm” package in Ubuntu: Confirmed Bug description: When using lightdm as default displaymanager X ends up with a dialog that tells me its in low graphics mode. If I then click on "run in low graphics mode" gdm starts up.. Lightdm used to work fine for me in oneiric. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/951555/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
