I tried to do that and I tried to restart my computer it still says the same thing ;~:It does the same for me as well sometimes. Just restart the game and it should be fine.
Remove the map in your files so it redownloads it. I had that with a VSH map. It redownloaded and fixed it. Or like Ruelel asked me to upload a map so he could download it and could watch a demo I had made. Maybe a friend can give you the mapfiles?I tried to do that and I tried to restart my computer it still says the same thing ;~: