If you cannot login to Xubuntu, Ubuntu then repair /home/user/.Xauthority
First open Terminal, Terminator or any Command line
$ cd /home/user
(change user with you computer username)
$ ls -Shla | grep “Xauthority”
$ mv .Xauthority .Xauthority.old
$ touch .Xauthority
$ chown user:user .Xauthority
(change user:user with you computer username)
$ sudo shutdown -r now
