chown username:username .Xauthority
Solution 1:
The command is
sudo chown roey:roey .Xauthority
1st roey is the user, 2nd is the group roey
Solution 2:
If you don't know what username/group you shoud use, I suggest using something like this:
sudo chown $USER:`id -gn` .Xauthority
-
$USERwill be expanded into your current username. -
id -gnwill returns the main group of your current user.