Is anybody else here no longer able to launch their own dedicated server?

Before downloading the DLC, I was launching my own server and basically playing single player via LAN, since doing so uncapped the 30FPS limit, and made the game ultra smooth. Basically, this: http://forums.steampowered.com/forums/showthread.php?t=1884049

The dedicated server, when I launch it now, just gives me an error message. Any thoughts or ideas?