Create a server

[Massas]

i currently have been trying to create a ftb infinity evolved server threw youtube videos, i've search everywhere but the server doesn't allow my friends to join, i tried via hamachi and its everything ok, they can see the server open but when they try to enter, they can't and appears that they have left the game but doesnt appear the message that he joined the game..
Any help ? Somene with the same problem that had fixed?
Contact me if u know how to fix : skype- jonapple2