I just updated my firmware ( June 23, 2016) hoping that would solve it, but "Network" is still greyed out in the setup menu. I need to get it on to use my phone as a video monitor.
Also, welcome to the forum. If you fill out your profile and add the camera gear we can better answer any questions that you might have. You can do that at http://nikonites.com/profile.php?do=editprofile
Under camera just put the model number like D7100; Once you put the first letter like D you will see a list of all the cameras in the database pop up. The more numbers you put in the smaller the list becomes. When you see your camera just click on it, Be sure to click on "Save Changes" in the lower right corner.
Thanks
And with the D7100 you must have the Nikon Wireless Adapter WU-1A I have a D7100 and the WU-1A and it is a little temperamental with my iPhones. The only way I can get it to work as advertised it to put the phone into Airplane mode before I try to use it. Once I do that it works pretty good.