Connection to host was interrupted [Crash Report]

[Curlystraw]

I remember playing forge multiplayer a few years back, and tried to set it up recently as my girlfriend's gotten into Magic. We keep running into the "Connection to host was interrupted" error, following these steps:

Host begins hosting at (external IP):36743
Client attempts to connect and joins the lobby
Players select decks and ready
Host clicks start

The host is taken to the playing field with the message "Waiting for opponent..." in the status box. The client is disconnected in the lobby and given the "Connection to host was interrupted" pop-up.

Error log attached as a text file because the forum reads part of it as a URL and won't let me post it.

As the issue might be with more modern copies of Forge, is there a legacy version of Forge that is known to have functioning multiplayer?

[yellow5]

I'm seeing the same thing, version 1.6.1. Log attached.

[Verusor]

I'm running into this same issue as well, and haven't yet been able to setup a LAN game at all. Not sure if I need to modify network settings, any help would be greatly appreciated!