try to fresh your password.
I just had similar problems here.
I turned on my laptop and strarted opera.
it had log out, all my open tabs had disappeared and i couldn't log into my account.
after retries and retries and restart of my laptop and moreover after i reinstalled my opera (up to date) nothing new happenned.
I just click on "i forgot my password". I set up a new one. And after all i am in now.
It seems to me that in order of a new policy about "password" -now it wants a lot of new stuff- it throw me out.
Can't suppose anything else...