The only time "I" have bumped into that message when being logged in on the site.
Is when I've been logged in on one account on the site, and trying to log in to another account in the game. With other words if I were you I'd make sure that you use the right account, and if you do, make sure you use capitalization correctly how your username is meant to be displayed on both the site and in the game.
You get half way through the connection, otherwise it would not have said request accepted. If it's not the account or how you log in with the name itself it must still boil down to your connection to the game server and it timing out before you get in due to bad connection towards it. As far as I know you as a user will see it exactly the same way as the server denying you for not using the correct username along with the play page on the site.