Nikon D750 Firmware Update23 May 2015 | Steve Thirsk
Nikon has released a firmware update for their 24.3-megapixel D750 camera.
According to their website it simply makes the DSLR 'more reliable'.
It doesn't give any more details, so, if you interested in making your D750 more reliable you may want to consider the upgrade.
More details and the upgrade can be found here.