So I attempted to have some of my fellow clan members try out my map tonight, but unfortunately it didn't go very well. Every time a person joined the server, they downloaded the map successfully, but at the end of the download they got the message "the map differs from the server". We couldn't figure out what was going on, as any other map we tried worked fine. Also, the map did download successfully, and every person could run their own server afterwards and play the map. I ran the compiler output on the interlopers.net error checker, and there were two errors. Here are the relevant parts of the compile log: Creating default LDR cubemaps for env_cubemap using skybox materials: skybox/sky_hydro_01*.vmt ! Run buildcubemaps in the engine to get the correct cube maps. Creating default HDR cubemaps for env_cubemap using skybox materials: skybox/sky_hydro_01*.vmt ! Run buildcubemaps in the engine to get the correct cube maps. 4 degenerate faces Neither of these seem to be that big of a deal, right? I've run buildcubemaps in game in the console after compiling, and interlopers.net indicates that the 4 degenerate faces are essentially no big deal. Any thoughts?