All of the BIS missions and/or community made missions get you booted back to the mission select screen when run on a dedicated server.
This happens immediately. You do not get any slot selection screen at all. This happens before any RPT information shown about the mission.
The missions still works fine in MP Client Host.
This is only a problem with Dedicated Server Dev Branch.
Terox Discovered this first with build 0.75.108541 (Introduction to the Steam Workshop Missions)
http://forums.bistudio.com/showthread.php?149636-Beta-Development-branch-changelog&p=2458820&viewfull=1#post2458820