You get that message because that part of NWN doesn't work properly any more. Just press OK, and then Join Multiplayer Game. Next you'll get Connection Failed Try Another Nick. Hit Cancel. With luck, you'll find Layonara under the History section. If not, then you need to know the address, which is 220.127.116.11:5121. The last thing you need is the password. It hasn't changed.
You can't go in game until you have an approved character, so you need to get through that process first. You'll get the password with your first character approval, if you don't remember it.
Good luck! I'm looking forward to seeing you in game.
PS - did you look in the character database for your old character? You might be able to get his history approved for a new character.