Disconnected in Zombies

[linguicaparmalat]

Hello, my friend can't connect to my server in lan (we use radmin)
I can connect in his server and play normally, but the game crashes after some minutes

My other friends can connect to my server with no problems, but only him can't connect.

This is what appears in cmd when he tries to connect 'client 1 disconnected, resetting team state.'