Same problem here.
Password manager worked always great till the last update. Since then it requests the password and also the user name.
Gave both correctly and Opera says it's incorrect.
Best posts made by gw009
RE: Problem with saved passwordsOpera for Windows
Wow, i just figured out, that this is indeed a massive bug and there is NO WAY to look into your passwords with Opera 49.
It does neither recognize your Windows username nor your PIN. It just doesn't work.
I needed a password badly so the only option was to install Opera 50 beta - there it worked fine.
Sorry, but this kind of bug is not acceptable. That was it with Opera...