Camera Raw still does not work with Nikon D750

How are you getting images from cameras to computer? If you're using Nikon software, try eliminating it from your workflow.

Camera Raw has supported the D750 since version 8.7. There are many users who are working with their  D750 for quite some time now. It would seem that there is some other problem with your system. Perhaps you are using  Nikon software to download your images.  If this is the case, it can be changing them  in a way that makes them unreadable  by Camera Raw. But your experience is not consistent with many other users.