Daniel K Loc: Albuquerque, N.M.

Is it possible to use my Godox V680II-N flash on a Nikon D850?

Magaliaman Loc: Magalia, CA

Sure, It'll work fine mounted on the Flash Shoe. You can't "radio fire" it remotely unless you purchase a Godox Trigger for your camera.

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

The adds for this flash unit states the following
"Fully compatible with i-TTL systems"
And Nikon D850 uses the i-TTL flash system.
So, based on the above information I believe you will find the Godox V860II-N fully capable of working properly with you Nikon D850.
But, I recommend using only Nikon flash units for your Nikon D850. Units like the SB900, or even the SB800. Great flash units that are designed from the beginning to work with you Nikon camera.

Retired CPO Loc: Travel full time in an RV

Yeah. And two or three of them cost as much as the camera. I use Neweer and they work fine at a 1/4 of the cost of a Nikon.

Daniel K Loc: Albuquerque, N.M.

I am pleased that I found the problem, but embarrassed that I didn't figure it out sooner. I purchased the camera used and it appeared to be in new condition; very clean. Upon closer examination of the hot shoe I discovered a small amount of dirt on it that apparently interfered with the contact. I'm surprised that such a small amount of dirt could have shorted it out. A Q-Tip with some alcohol did the trick. Thank you all for you assistance. A Merry Christmas and a Healthy and Happy New Year to you and your families :-)