See unit markers on vet/Weapons do no damage

[mr_h 1]

I'm trying to track down the cause of this problem, but I'm not sure where to start looking.

Situations: Friends and I use the same mod set via Play With Six. We load into a multiplayer server running a mission we designed. Everything is fine with them, however: 1) I see their unit location markers (the little green dots), despite the difficulty level being on Veteran, and 2) My weapons do no damage. Switching to grenade and throwing one goes through the animation, but nothing is thrown.

I have restarted the mission/arma with Play With Six several times and it fails (though one time it started to work). Recently I loaded the game via Steam with the mods on the command line, and it worked.

Im a bit confused to the cause of this problem and I'm wondering if anyone can help me look for logs or whatever might be causing it.

Arma 3 standard build. USing mods freely available on PWS and all my friends are using as well (Acre, CBA, weapon rest, STHud).