I've just experienced the same story as Mr. Bruno Nova (brunonova). I spent a whole day to shoot the trouble and identified that it's about .Xauthority.
I tracked the /var/log/lightdm/lightdm.log and looked into my .Xauthority. I found it contained two entries: snow/unix:1 MIT-MAGIC-COOKIE-1 f8aa6a272ab2e68533175967a9e5d09d snow.mydomain.com.tw/unix:0 MIT-MAGIC-COOKIE-1 1e9a7aeba63b74bef069a3629fe3e80a Removing the 2nd entry, which should be 'snow' instead of 'snow.mydomain.com.tw', made my system recover and logs me in again. (Usually I am the only user of this machine. The :1 entry is created when I successfully login with a new test account, and switch to login my normal account.) I don't know when it was touched and by whom. I have tried to reconfigure postfix the other day. I have changed my /etc/hostname from snow to snow.mydomain.com.tw, but I changed it back later... I think short hostname is better for my administration. Such condition rarely happens. It looks .Xauthority is seldom updated except necessity. However it(the greeter?) could be more robust for such cases. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1234400 Title: Cannot log in users if their Xauthority file is corrupt. To manage notifications about this bug go to: https://bugs.launchpad.net/lightdm/+bug/1234400/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
