OpenRA

Hello everyone, i was playing a match with 4 of my friends, everything goes well unitl after 20 minutes, we all get the message:
Out of sync detected at frame 12162.
The game was still running but it froze, saying one of my friend paused it.
What does this mean, are there any logs I can share with all of you so you can understand it better? Is this common at all?

Generally games desync when one of the players has a modified client (modified game files). In other cases desyncs seldom happen and are hard to diagnose