as of now. I managed to solve the problem. I hope it stays this way.
First, i needed a clean windows install. win 10 pro
New user with Admin rights. Altough my original user is admin too.
Cheked warhammer and log in user/doc and certificates were missing.
Then i downloaded the certificate linked by Megapull in steam topic at 2018 may 3.
Added them in windows. and it works..
Anyway, i could log in once. But previously i could log in as well, then never again.
Took me almost one day to fix it, i hope it helps for anyone with this issue.