I have a rather large map that I have been working on for the past few days and to do a test entity compile, made a gigantic box around my level and compiled, as I don't have the outer sky walls in place. (To be removed once I test this entity setup, don't flame me on why this is bad, please.) Compile runs fine, no errors or anything, and only when I go to test my map I have an error. Steam gives me a 'Fatal Error: File Read Failure' shortly after I type 'map d3' into the console. I am speculating this isn't due to my gigantic box, as that would cause a rendering error or extreme lag in the engine, which is what I was expecting. Tommy14 suggests a corrupted HL install, though it can run other maps fine, viruses, though I did a scan and have none, or other issues which are not applicable or nonexistent. I've compiled with only two wads, halflife and my custom.wad, although one of the textures is probably larger than 512x512, I haven't checked. Could that cause an error?