we could play together fine until we restarted the game and now there seem to be incompatible versions on steam and gog.

I guess there is no option beside waiting for gog to release the same patch version or buy it on steam...

patch is out, get updated, have everyone turn off auto-update.

Yes, same for me.

We are at the same game version but the "mod server is different GustavDev:4.0.100.xxxxxx for my friend and GustavDev:4.0.15.xxxxxx for me"

I guess we have to wait a patch deployement, or buy the game a second time at Steam ...

Exactly the same error for me, with exactly the same versions in the message it is clear that even though the game versions are the same internally they must have different versions when creating the server. I hope they fix it soon because yesterday it was perfect.

Exactly the same issue here. I'm on GOG and my friend on Steam. How did you do the first time ? With direct connection (and the code ?).

Same GustavDev error like you. But that's the first time I try to create a coop game, yesterday I was playing solo.

Yes, Direct Connect seems like the only way to play cross launcher.


Also, here is a possible fix for now:

steamcommunity.com/app/1086940/discussions/0/3808408328764266215/

This fixed the issue for me, thank you!

Oh thanks a lot ! IT WORKS !! ♥

Her is the file as a .zip

Sorry, apearntly cant post the file here.

Here the one I use from my friend (but if you dont play with someone from Steam, why do you need it ?)
https://wetransfer.com/downloads/222d44cea7abc8a977f169574ff9466a20230804204913/572778

It works. I'm on gog and 2 friends at steam. they created the game and i can join with no problem.

OBS: the GOG identify thats a differente file in the local installation, just ignore the warn and go on.

The latest patch on GOG added this file and there's no need to copy it
If you're not seeing it, I would suggest you click on Manage installation - Verify / Repair