I set everything up correctly (I'm pretty sure anyway...) and I went into Hammer from the alien swarm SDK and made a simple room with an info_player start. When I try to compile however, it doesn't seem to work. I checked, and I couldn't find a bsp map file anywhere. This is what the compiler says EDIT: I opened the example map from the zip file posted earlier, and that compiles fine. I assume it's a problem in my test map, any ideas on what it could be?