From the Error message you are getting it seems that you have drive/folder permissions problem.
Please state the exact path to the folder those images are held in. The error message states Volumes/Nikon D7100 which to me looks like it is the actual camera. Like you imported those images from the camera without actually copying them from the camera to a folder on a drive that is connected to your computer.
Also, you may try and update Lightroom to its latest update for 6.10/2015.10 and check if that helps.
Good work my friend. I have no earthly idea how that happened but Lightroom was importing but not copying the file onto the computer. I had always thought importing meant like you know.. Importing lol. Yes this was the issue as soon as I pointed it back to my 2017 folder everything worked just like it should. Thanks for everyone's help!!