I was making some changes recently, trying to rename my user account from the macOS High Sierra System Preferences, and it seems I've locked myself out from making any changes to Users & Groups now.
When I click the lock icon (
Click the lock to make changes) I am prompted for a User Name and Password. No matter what I input in these fields I am unable to unlock the preferences. I am sure I know my user account, otherwise I wouldn't be able to log into the computer, and there is only 1 user on my Mac.
I've also tried with:
sudo dscl . -merge /Groups/admin GroupMembership <username> Password: <username> is not in the sudoers file. This incident will be reported.
So it seems the name change is causing a mismatch between what's in the sudoers file, so I basically have no user with admin access right now.
Does anyone know how I can reset these, even from the command line? Thanks in advance!