In order to use Nikon D750 for tethering you need have Lightroom 6.0, as it will not work on Lightroom 5.7
Please check the following link for the list of supported Camera by Lightroom : A list of cameras that can be tethered to Lightroom.
So I will need to upgrade to Adobe CC to get it to work? Any other options
for tethering the d750?
Owner / Photographer
Squaw Creek Photography
Yes, you need to upgrade to the latest version of Lightroom or you may check if the Nikon provides a software for tethering.