I backed it up and tried to Reset it to factory default.
This triggered Avast Mobile Antitheft, which seems to have erased the configuration data on the phone. Now, instead of a fingerprint, it wants a password to unlock the phone. We assume that it wants the backup password that one uses in case all your fingers have fallen off and gotten lost.
Problem is, that password is similar to this 1234Word with a capitol letter and about 6 letters. YET, the ONLY keypad is just like on a telephone.
1 2ABC 3DEF
4GHI etc
So, IF that is what is happening, then Catch 22. You can't get there from here.