Problem reading SanDisk Extreme Pro CFexpress card

I have a Nikon D850 and have been using a Sony 120GB XQG card without any problems for over a year. I recently purchased a SanDisk Extreme PRO 128GB CFexpress card. When I insert the card into my XQD card reader it does not show up on my desktop. I then put the CFexpress card back into the D850 and connected it to my imac 27" and still no luck. My imac is running 10.15.7 and the D850 has the latest firmware. I'm have a hard time finding answers on the internet. I reached out to SanDisk and all they said was to return it to where I purchased it, or send the card back to them. I am not getting any answers as to why I am having this problem. So my dilemma is, do I wait and try to iron out the SanDisk issue, or do I return it and purchase a Sony card? What guarantee do I have that the Sony will work?

It is unlikely that your CFexpress card will work in an XQD card reader.

That was my first thought. But wouldn't you think that it should work hooking the D850 up to my imac?

Errr, just checking but does the CFexpress work OK in your D850? You imply it does but thought I'd check.

 

That was my first thought. But wouldn't you think that it should work hooking the D850 up to my imac?

 

The fact it doesn't show as an 'External Drive' or whatever a Mac calls it is odd, as theoretically, it's the D850 talking >< to the Mac not the card directly.

 

Other check, find a friend with a PC....;)

I feel that the card is working in the D850 because I am able to scroll through my test shots in camera.

By the way, I just ordered a $40 CFexpress card reader. Hopefully that works and problem over.

It may have nothing to do with your problems, but in my experience the cables connecting card readers to the computer fail at a very high rate.

 

Also, I think that best practice is to reformat the card periodically, and I also have a dim memory that there is a finite number of re-formats possible..?

Is your Sandisk card on the Nikon supported card list?

For Sandisk Extreme Pro there is a disclaimer:

It may have nothing to do with your problems, but in my experience the cables connecting card readers to the computer fail at a very high rate.

 

Indeed.. Does the OP use the same cable to connect the card reader and the Camera to the PC?

If so , try another cable ?