at the top of the support section, there's a thread called "Sticky: SOLUTIONS FOR CONNECT PROBLEMS, READ BEFORE YOU POST "
https://forum.nostalrius.org/viewtopic.php?f=45&t=5359If u read it, you will see something that can help u :
2. If you have been online and now cannot log in or are logging in to incorrect realm, the simplest solution is to close WoW and navigate to the WoW folder and throw away your WTF folder. Reopen WoW and you will be prompted to select realm again. You can also attempt to hit "Esc" while logging in to try to toggle yourself back to the realm selection screen. * Select US & PVP to choose the correct server.