Did you use Nikon Transfer to get the files from your camera to computer?
If you get the files off your camera without using nikon transfer do they open in photoshop cc?
I was able to open newly created Nikon 800E NEF files copied directly to my computer bypassing Nikon transfer. Your answer suggest that Nikon transfer modifies the files? If not what is going on and how do I open NEF files transferred with Nikon transfer?
An obsolete version of Nikon transfer, one that came with your previous, much older, Nikon camera, does erroneously modify something in the header of files, that makes the unrecognizable to Adobe software. If you want to use Nikon Transfer, use the version that came with your new camera.
You can correct this corruption issue using a utility at the following location:
I expect you’d want to use the 14-bit option.
Thank you, for your help, explication and the link to the support tool!