Failed to start session (Was password fail)

[Grizzly]

Hi

I thought I  had a password problem after upgrading to 22.04 (it ran fine while 

I updated with many re-boots) now I get

Login UI with password request, after entering correct password, I just get 
"failed to start session" in pink above the entered password (I misunderstood 
it as a password fail) in the same box

I have tried making a new user, but that user gets the same result

I get no other indication what is going wrong or how to correct this