[Help] Making it so other players can play [Hamachi]

Could someone please tell me how I can allow other players to play on my server through hamachi? I have everything set up and I can get on my server but when I sent the client to my friend, and connected him to my hamachi he got the server maintenance error.

Check if all the files have the correct hamachi IP in them and make sure the oem.ini/dat in client has the hamachi IP as well.

and join him in a room @ Hamachi