Board Thread:Servers/@comment-25528679-20141012044543/@comment-25532971-20141013074622

I see your problem. Remember the folder labeled 'Terraria' that you dragged the N Terraria files into? Go to that, and run the NTerrariaServer.exe. It's the only way to really host a server, since Host & Play doesn't currently work.

Hope this helped.

EDIT: Oh yeah, you will also need to use your IP in the 'Join' part in Multiplayer, since you can't play the game from the server, just set up multiplayer with it.