Having this problem with my mission on a dedicated server.

If we change the params for the server, but keep it on this mission file, on the first startup of the server afterwards, we always get a "No Message Received" followed by a server crash. Then, after a server restart, we get this issue:

Me and a friend load onto the server and after about 5 mins in the mission, the server FPS/CPS will drop to single digits and then we are both frozen for the other person i.e i can move around and fire, but my friend wont see me moving or firing. We've been through all the scripts and optimized them and it's still happening.

Dedmen also suggested for everyone to disable the Units for each person who joins. This however did not fix the issue.