A few friends and I picked this up on GOG with the express intent of playing MP.

So far it's been... OK. Getting a game going is smooth and reliable, but once in game we seem to error out frequently with random "X has been disconnected from the lobby". Sometimes there is no notification that anything is wrong for the dropped player, sometimes a red box pops up with "GOG Failure (0x03, 0x00)" which is not particularly helpful for troubleshooting.

Anyone have any MP experiences to share? Any idea if anything MP related is logged on the ES2 or Galaxy logs? It would be great to have stable MP, especially considering that Amplitude is working on The Last Patch which should clean up a bunch of longstanding issues.

Same error, many desync at the end of a turn and few times the same pops failure message

The game is unplayable MP, especially after a few turns, the game unsyncs all the time, with different flavor of errors

Did anyone give support a chance to fix it?

Well if I knew what Amplitude was, and if I played MP, I guess I might. The GOG error message might imply that GOG would be interested to hear about it, though. And I've had mixed, but sometimes very good results from the GOG support guys.

Amplitude is the company that wrote and published Endless Space 2. I suspect that they are also the ones who did the conversion from the steam multiplayer/network API to GOG's. However, that is just my assumption. It is possible that someone at GOG did the conversion, so opening a GOG support ticket isn't a bad idea.

Fingers crossed.

Welp, I opened a support ticket. GOG's support bot needs to go die in a fire.

Yeah it's maddening to get through that stuff to where you can correspond with a human. And sometimes the human must repeat a few iterations of what the bot has already been telling/asking you (unhelpfully) before they get down to business and listen. Good luck!

So after a bit of back and forth with GOG support and some trial and error in the game itself, we were able to get very stable gameplay (still the odd desync, usually combat-related, but nothing a save & rejoin didn't fix).

The key turns out to FOLLOW THIS GUIDE, to the letter:

https://gameplay.tips/guides/9277-endless-space-2.html

With that, the GOG version of the game is at least as stable as the Steam version.

Hope this helps anyone else experiencing disconnects / kicks!