Board Thread:Bug Reports/@comment-29716003-20160826010216/@comment-27219153-20160827190817

Before he joins the server, he is getting something that looks like this correct? Is he using a cracked launcher or account? I still think the console would say something if he was though. Since the IP is clearly working, perhaps its an issue with that particular port? You could try a different port, if you are able to change it.

I'm pretty sure that if you were to change the server to vanilla, he would still have the same problem.

The last thing to check would be the client game output. Make sure the launcher stays open when launching minecraft. This can be done from within the profile editor. Then post everything that is outputted when he clicks on multiplayer as well as when he attempts to join the server.