[1.3.1] Severe but random player lag

[FriendlyFire]

So we've been trying to play a few games in multiplayer and we very frequently run into an issue I haven't seen documented yet.

As soon as the game starts (doesn't matter if it's a new game or a save game), some of our players will lag behind significantly (goes up to 3-4 days then the game slows down dramatically to prevent further desync), making the game unplayable. This is not performance related since we're getting it with new games and the players with the worst internet connections aren't the ones getting the issue. Some players seem more likely to have the problem (I'm hosting and never have it obviously, another player has never had it, and two others have it randomly). If the problem manifests, there seems to be no real way to fix it. We managed to fix it once by just restarting the game many times and checking local cache, but the problem manifested itself again the next day, so we're not sure if it actually fixed anything or just randomly decided to work.

We really have no idea what's wrong at this point. We're playing with mods (minor visual and UI mods), but tried without and there's no difference. We tried reverting to 1.3.0, no difference either.

 

[AndrewT]

Does it matter who is host? Generally you want the host to be on a slow machine or connection, so the others have no trouble keeping up with it.

Other general MP guidelines:

- make sure all players have opened the required Steam ports in all their active firewalls (each player may have up to 3)
https://support.steampowered.com/kb_article.php?ref=8571-GLVN-8711
- use no mods at all
- all players use the same language in-game
- when anyone gets an OOS error, re-host the game immediately, as it will almost certainly crash soon
- start your multiplayer games and wait half a minute or so before unpausing without any player performing any action at all. Only after the game has been unpaused should players begin doing actions like setting research, exploring etc.

Good luck!

 

[FriendlyFire]

Thanks for the answer!

We seem to have "solved" this by making him host a game, I join, then we quit and I host our real game. This consistently fixes the issue, though it's obviously not ideal. I'm suspecting that doing so is opening some ports when he's hosting, and those ports will remain open until he's shut down the game.