http://steamcommunity.com/profiles/76561198013756738/screenshots/ As you can see from the screenshots, there seems to be a few places where the brush doesn't render. However in hammer they render fine. They are parts of the brush that they appear on, so something must be going wrong when the map is being compiled. Running the compile log through interlopers.net gives me this error... zero area child patch Description: A solid in your level has a face with no area. My guess is that vrad.exe is trying to create a lightmap for a face that doesn't exist. Maybe you have an invalid brush? Solution: First check Hammers problemchecker (alt+p). If that doesn't solve your problems, you can either ignore the error, or try to find it anyway using cordon tools. You would be looking for brushes which might be too complex. I wouldn't recommend the second option. Anyone know what is going on and how to fix it? Unrelated but critical for the map. When I compile the map, the map works fine for me. However when I give it to a few beta testers, they say that a part of the map that I say should move doesn't move on their end. They get some sort of console error saying that the logic_relay doesn't exist. How can I fix that?