Nostalrius Begins - Quality wow vanilla realm (1.12)

I cant login i get disconnected instantly when i try to connect the PvP server.. anyone knows whats going on?

Have you tried running your WoW client as an Administrator?
That might help, also do you have any addons that could be effecting your connection?

If none of those are the issue have you checked your Firewall to make sure WoW isn't blocked?
Also have you tried deleting you WTF folder?