I run a dedicated server and have for a while now. It's using the Linux binaries but runs on FreeBSD (which I know is a weird setup, but it hasn't caused many problems before, though I suspect it's to blame now...?).
Anyway, since the Night patch, sometimes enemies will be invisible for some players, but not others. In the kill feed, the player will die from [AKM (or whatever)], with no class attached to it.
A second problem is that sometimes the class menu will never spawn.
Either of these problems seems to happen every 3 or 4 games. It's resolved if the affected player disconnects and reconnects.
I assume it's my server setup since no-one else is having the problem, but seems worthwhile to mention it...