Solved: Don't use ported game content, TF2 doesn't mesh with their models. I've finished a 3 stage map after about 6 months working on it and I've come to an error when trying to load the map with sv_pure 2 enabled, this error does not appear with sv_pure 0. With sv_pure 0, I can load the level normally after I've packed all custom content. Trying to load the level with sv_pure 2 enabled gives me this engine error and promptly crashed the .exe: "Failed to lock vertext buffer in CMeshDX8::LockVertexBuffer.nVertextCount=2204, nVertext=0" I googled some help to no avail, and my map size repacked is 82KB, slightly larger than cp_egypt. Overall I made the primary engagement range quite large, and I'm unsure if I'm breaking some engine limits or this is just a problem affecting me. I want to release my map without any errors like these. Here are two screenshots of the map if that helps gauge an issue. I'd be appreciating anyone with some know-how on this error for help.