I was making some changes recently, trying to rename my user account in 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 Name, 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?
System Preferences → Users & Groups, check your account type. Is it standard or Admin? – Nimesh Neema May 08 '18 at 12:15