When I start my MacBook Air (Mojave), I see the correct list of accounts from which to choose.
If I choose my SysAdmin account, it accepts the password correctly, the horizontal progress bar advances to the end and then it redisplays the login screen with the list of available accounts - but MINUS the SysAdmin account.
If I logon with another account which has admin privileges and look in Users & Groups, I see all the accounts listed, minus the non-functioning SysAdmin account. I see the same list of accounts in Users & Groups, with no SysAdmin account listed, if I don't try to logon to the SysAdmin account first.
I have created a new Administration account (with a slightly different name), which works fine.
How do I remove the non-working SysAdmin account from the account list that appears when I start my Mac, as I can't find a way to see it in the User & Groups list?
Many thanks !