So... we still have problem, it turns out. Using VIDE to pack content into my map seems to have gotten everything except one of the sound files. It's referenced not by the map itself but through a custom level_sounds.txt override. Packing level_sounds.txt itself was no problem, since it clearly knows it's supposed to be looking for the custom sound file when I trigger it. But there's no sound, and the console says it can't find it. It was packed from the same location as the other sounds, which all work correctly. It's listed right there in the pakfile. I really don't know what else I could try at this point.