Either some vital data was lost in transit between players, or your data/game version don't match perfectly (it could also be caused by a user attempting to cheat, but that's not very likely).

The way the game works is that everyone is basically a server unto themselves. The other players send data over and your machine gives the appropriate orders/movements to the "them" on your copy of the game. Because of this, if some of those orders get lost or the same action does not cause the exact same result on all players' machines, you end up losing sync.

Once a game has desynced, it cannot be recovered. As time goes on, what you see and what another player sees will diverge more and more, even up to a point where the entire outcome of the game may differ. So if you get a desync, there is not much point in continuing to play that match.

Well I got Polish friend also, who changed his game language by replacing original US language file by Polish file. At the end of the game (when citadel was destroyed) he ALWAYS got desync (sometimes in the middle of game also). When he repaced this file again (to get original state), all worked perfectly. He tried this trick few times and replacing file to Polish always caused problems. I dunno if that's Polish language file issue or you just shouldn't replace any in-game files (including language). But im 100% sure it's something wrong here.

I'm glad i could help.

But well, let's face the truth. For people who especially BOUGHT Polish version of the game, it's a bit frustrating issue, to not be able to play with their own language (I know not all people has this language problem, just some of them). My friend was really dissapointed after we found this issue - he don't speak english very well, so fully english in-game language overwhelming him a bit. He was forced to use english language, to not get that desync error.

thx all

i got that message some games but then i got thet every second cant play this way with some people.

dont hope there cheating it woult be fair.