Yesterday I upgraded Ubuntu to 18.04 . Today I logged out and tried to login by giving the password. Password is correct and it seems to be working and suddenly it comes back to login screen. When I entered a wrong password, it shows that password is incorrect. So I can't login now. How can I fix this? Any help would be appreciated.
EDIT : followed [this]( Ubuntu gets stuck in a login loop) question and tried the answer. Tried chown username:username .Xauthority and it gives an error saying, changing ownership of '.Xauthority' : Operation noy permitted.