Here is a link to inform you about the most recent firmware updates for Nikons:
https://www.dailycameranews.com/2017/03/nikon-d7200-d500-d750-d810-wt-7-firmware-updates-released/
https://www.dailycameranews.com/2017/03/nikon-d7200-d500-d750-d810-wt-7-firmware-updates-released/