Problem Lost connection to server

[Raging_Lynx]

When my friend tries to join my server he gets this message:
gribble4 [/25.7.159.76:55432] lost connection
2014-05-29 18:47:29
I really have no idea what do do. please help

 

[SoraZodia]

Did he have the correct modpack/ mob installed?
Also are you hosting your server on your computer? You would want to check your port forward settings if you are hosting the server.

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