Nostalrius Begins - Quality wow vanilla realm (1.12)

I just downloaded Nostalrius, put in my name and password when opening the game but it says invalid, even though I can post on the forums here, which means I've a valid account, right?

It tells me to get help at European WoW battle.net forum, but I thought this was separate from official Blizzard game?

Anyone have an idea what is going on here?

Thanks.

Your forum account and game account are separate. You can apply for a game server account at the bottom of the front page: https://en.nostalrius.org/