Nostalrius Begins - Quality wow vanilla realm (1.12)

Every time I try to log in, after I enter my password, it always says I have been disconnected from the server. I have even reinstalled. The server says it's a devs realm by the "Quit" button. It just randomly disconnected me from the game, then when I tried to log in at the begining, it kept giving me a realm list, and I kept picking random ones. Ever since I picked the dev on, it keeps saying I have been Disconnected from server. Why is this happening to me?