I'm trying to set up my new Mac Pro (6c, 16gb, 512gb, D500) with windows 8.1 via bootcamp. But I'm getting an error message during installation saying "cannot update boot configuration", and it just gives up. I've tried making my own partition with disk utility but to no avail. I also tried to DL a different iso but that's giving me a whole other set of problems and failing before it even finishes preparing everything for the install.