22.04 login problem

[Grizzly]

Hi

An odd one that is driving me mad

I upgraded Unity 21.10 to 22.04 (also Unity luckily) rebooted many times, left 
it and came back today, now I can't login now, dialogue reports "session failed 

to start" or similar wording as I'm not on that box (duh)

I went the normal route for a password problem, boot from live (or another 
Ubuntu that duel boots) reset password, try again to login, still no change

Anyone else having this painful error