Cannot unlock Users & Group in System Preferences I was making some changes recently, trying to rename my user account from within macOS High Sierra System Preferences, and it seems I've locked myself out from making any changes to Users &amp; Groups now.

When I click the lock icon (Click the lock to make changes) I am prompted for a Username 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.
That fix is actually simpler than you might think, though it does call for a reboot, two if you want to be technical.


Reboot your Mac while holding CommandR This will boot you into recovery mode.
From the Utilities menu select Terminal
type resetpassword and press Enter
The password reset utility will launch. Follow the prompts to reset your password.