I wonder if it's the contacts.
I had the same sort of thing happen when I first got a Rokinon lens. On my Rokinon 35mm I set it to "A" above F22 and then it worked fine. (I have to hold down the little metal button to get it to "A".) Not sure if this lens is different. Some you set to F22. I also enabled the camera setting that allows you to use the aperture ring manually.
The only other thing I can think of is setting the camera to Aperture Priority or Manual mode. And maybe manual focus.
I have a Pentax K-5 so don't know much about Nikon settings.
I returned it already...it might've been the contacts . I had to put a lot of pressure to screw the lenses in... It was more than a tight fit.
Ohh well at least they took it back without a restocking fee or having me pay for the return. Buy dig took care of everything