I cannot login to the old username because it does not exist on the login screen. I cannot recreate the old username because I don't have root privileges. I have tried many methods of getting to root mode and none work. Is there any way of changing the new username to the old one?
I usually get this message:
sudo: error in /etc/sudo.conf, line 0 while loading plugin `sudoers_policy' sudo: /usr/lib/sudo/sudoers.so must be only be writable by owner sudo: fatal error, unable to load plugins