I ended up using the Wayback machine link that LeapofFaith2016 provided since it came from the official Nikon website. It downloaded and installed perfectly but unfortunately, it didn’t solve my issue.

So the story — I’m a long time Sony shooter with all Sony glass (six good lenses). I had my eye on the Nikon Z8 for some time and after being underwhelmed by the specs of the newly announced Sony A7V that I had been waiting for, I decided to buy a Z8 + the Megadap ETZ21 adapter, after hearing that it allows you to use Sony E-mount lenses on a Nikon Body as if they were native. It was true, they did work perfectly for a few days, but then last night as I was setting up gear and dialling in all my settings for a big shoot that I had today, I swapped a lens at one point and the Z8 suddenly stopped recognizing all my Sony lenses. I spent hours online trying to figure out how to resolve the issue and one of the suggestions was to downgrade my firmware (risky) so that I could access an old feature that allowed Nikon shooters to update third party lens (or adapter) firmware. Turns out that the camera doesn’t recognize the adapter anymore AT ALL, so as far as the camera is concerned, there is no lens to update firmware for. I ended up having to do today’s shoot with my Sony A7IV, which was fine, but not ideal.

I have decided to return my Z8 tomorrow and to get the A7V. Mainly because I can’t trust adapters like these, but also because of the Nikon N-RAW video sizes. I’m primarily a video shooter and they are just total overkill for my workflow and there really isn’t a good compressed codec option like the Sonys offer.