I have downloaded a WaW save and changed the Ids. Now when I go to save it to my Usb there is no save. And it doesn't work if I drag it.
Try using Horizon. Open Your save, then open the modded save. Transfer the ID's from your save to the modded save and save to your thumb drive. Rehash and resign... Hell with it Rehash and resign again to make double sure... never hurts.. Try this bro and see what happens.. If it doesn't work I would question the functionality of the modded save you downloaded...