Disconnected by host D:

When my friend attempts to join my lobby, I see his username for a split second and then it disconnects him, it tells him "Disconnected by host." This doesn't happen when we play minecraft, or a other game. So its the game that's doing that.
We use evolve and were in the same party. Please help us anyone, we prefer Crusade over super smash flash 2, so we REALLY want to play this.

First, you guys need to make sure you have the exact same version. You can download the most recently patched version somewhere here in the forums, conveniently.

Also, give it a shot with Hamachi.

Who do you main, by the way?