Hey there. I don't know how much multiplayer is supported or how much the devs can do to fix these errors, but the info might be helpful for others playing multiplayer who want to know what to avoid... So I'll post it up anyway.
We've actually been able to play some long stable games in Renaissance, but at a cost... We have to avoid certain things and thus lose large sections of game play. The biggest one is dynasties.
- Avoid getting married. After extensive testing we are certain this consistently causes an out of sync error. Often almost immediately. Doesn't matter which player is getting married or to whom. Occasionally (though not often) we manage to get through the wedding ceremony without an out of synch error. Even with reloading saves made after the wedding, it doesn't last though. We always get an OoS error within a few hours (by the game clock, so a couple of minutes real time) after the wedding. I suspect the error is triggered by the adding of the knew controllable character to the players party (If not the dynasty in general). Easy to avoid, but we have to use an immortality cheat and be careful with our lives to make the game last more then a generation.
- Council meetings. This one seems to be long recognised. What seems relevant is though we did get them in our first couple of renaissance games, we haven't got them recently. I suspect this is because we don't have any AI dynasties in our last couple of games. So it is possibly related to AI dynasties attending the meeting at the same time as the players.
- Capturing buildings. We haven't had time to test this yet. But out last out of synch error occurred while one of my thugs was trying to capture an AI run church. Might be worth noting that the church had repaired itself but the thug was carrying out the capture command regardless. I'll try test this some more and update this when I have.
- Autosaves. Although highly useful if there's a crash or OoS error... I find autosaves seem to cause as many problems as they solve. The only crash to desktop I've experienced while playing renaissance was while an autosave was taking place. In two instanced we've suffered OoS errors immediately after them as well (though not on reloading them). You might be better off disabling them and saving frequently. Every time I here the bells chime just before midnight I manually save. I also try to manually save right before council meetings, and trials if anyone is attending them.
OoS error solutions: Avoiding these things we've logged over 18 hours of game play without OoS errors... Though not being able to start a dynasty is a huge drawback. One solution suggested if you don't have a recent save and an OoS error occurs is to have the host save the game and then send the save file to the other players. That is a huge hassle though.
If the developers can manage it, I think it would be great if people in the lobby of a multiplayer game that has been created from a loaded game by the host, could automatically have the save game downloaded to their computers with transfer status noted in the lobby so the host knows when all the players have it and are ready for the game to start. It would save allot of time and hassle getting an OoS game up an running again.
