My one friend (a Win 10 user) joined in an unmodded game of another friend (a Win 8 user), and I joined him, too (I'm also a Win 8 user). I had no trouble, Win 10 friend had to download/install Patch2.pak, and when he finally got into the game, anytime he got wet (stepping into the ocean, for instance), he became Invisible; he also reported we were source infused, when we were actually source muted (beginning of the game before getting the collars off)... but it was only on his end. It was unplayable for him. Win 10 friend and I did a search, and the Patch2.pak stuff started after the Dec. 5th update.
Also, anytime I tried joining a game of his, I had to download/install Patch2.pak, even if I had already fully downloaded and installed it before, but no weirdness came on my end...
I hope that's a good starting point for Larian's search for the problem, because whatever this bug is, it SERIOUSLY needs IMMEDIATE attention, as it's affecting a whole community of gamers.
Why not revert back to the previous update (Before Dec 5th, when these problems started), and rebuild from that point? Or even make a test server for said rollback to make sure? I LOVE DOS2, but this is just making me feel nothing but frustration from the game anymore...
