Unable to login

[Jerry]

I recently updated to FreeBSD 12.1. Everything seemed fine at first.
Now, quite suddenly, I am unable to login to my system.

From a cold boot, the login screen appears. I type in the name and
password, and a new login screen appears, The time of my last login is
updated though. It appears that I am being immediately signed out of
each session. I am caught in a login cycle.

What can I do to correct this?

-- 
Jerry