Upgraded to OS X El Capitan.
Ran for about an hour and then wouldn’t let me sign on to my primary id.
Luckily, I have always followed a rule of thumb with all OS’, “create multiple admin and regular User accounts”.
So I was able to log on an alternate administrator account, so the problem was limited to the MAIN administrator account.
I could not reset the MAIN admin account from the ALTERNATE admin account.
So since I use LASTPASS and keep all my old passwords, I just found the prior one which was the ICLOUD password.
Bingo that was it.
So, make sure you know that one, because OS X El Capitan resets it back when you upgrade.
I guess that’s a “feature”.
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