I don't want to confuse things but according to Adobe support, as of Dec 2015, the D750 was not supported on Windows 10, yes with the latest version of LR. Here is my transcript of the call below.
It's a year later and I had a need to tether once again. For me in the same scenario it still doesn't work, yes with the latest version of Windows 10 and LR. I can import from the camera while USB'd to the PC and Windows sees the camera in Explorer.
I'm going to try one more troubleshooting technique listed here
and report back if it works.
Here is my transcript of the call below.
For additional help, reach us at http://helpx.adobe.com/contact.html
Chat start time
Dec 18, 2015 6:38:39 AM PST
Chat end time
Dec 18, 2015 7:32:39 AM PST
Duration (actual chatting time)
info: You are now chatting with Alok.
Please don’t close the chat window or browser tab since it will end our chat session.
Alok: Hello! Welcome to Adobe support.
Alok: One moment while I look up your customer record
Alok: If I am correct you are unable to tether your camera from your Lightroom .
john : Y
john : es
Alok: Could you please tell me which camera are you using ?
john : Nikon D750
Alok: Could you please tell me since how long have you been facing this problem?
john : I've spent 2 days trouble shooting and researching on line so I need something more than the basics to resolve this.
Alok: Please allow me some time so that I can check it issue .
john : Thank you.
Alok: As I checked the Tethering problem is still going on and our engineering team is still working on it .
Alok: I apologize for the inconvenience.
Alok: It might be get resolved in next update .
john : I'm confused. Are you saying that tethering with the D750 is a known issue?
john : Wow! Where is that stated? I wish I had known.
john : Hello?
Alok: Yes I am here .
john : Can you tell me where it is stated that tethering with the D750 in LR is a known issue?
Alok: Please wait.
Alok: Please go through this link and check that windows 10 is not supported for Nikon tethering .
john : "Expected to work on all OS versions supported by Lightroom 6"
Alok: Yes our engineering team is still working on it .
Alok: It will be available soon.
john : Can you add me to and email list alerting when its corrected?
Alok: Yes you will get a notification of the update in your creative cloud .
Alok: You can check which update you got for your product.
john : I know you don't deserve the grief, but there is no mentioned of windows 10 anywhere in that document, so you could use that doc to say tecthering doesnt work with any camera in Windows 10! True?
Alok: It is clearly mentioned .
Alok: D750 6.0 Windows 8.7; Mac OS 10.10.2, 10.9.5 Expected to work on all OS versions supported by Lightroom 6
Alok: You can check it one more time in the list of Nikon camera.
john : Are you clear that I am taking about "Windows 10", There is no mention of "Windows 10" in that line you just copied and pasted.
Alok: Yes it is saying that it is tested on windows 8.7 it means it is not available for windows 10 .
john : Ok, first of all, Windows 8.7 is a typo, there is no 8.7, right?
Alok: Sorry You are correct .
john : Thanks. It would be helpful is Adobe came out and said tethering is not supported on Windows 10.
john : "Tested on Win 8" is not that same as "not supported on Win 10".
john : I'm not trying to be difficult.
Alok: Thank you for your valuable feedback we will work on it.
Alok: I understand .
Alok: Is there anything else I can help you with?
john : Ok, thanks, so we can end this call, you are saying that tethering on Windows 10 is not officially supported. Yes?
Alok: Right you are correct .
john : Thanks you.
Alok: Your most welcome.
john : we can end this call. bye and have a great holiday.
Alok: Thank you for contacting Adobe. We are available 7 days a week, 24 hours a day. Goodbye!
Nikon D750 is supported in Lightroom 6(since version 6.0). Please update Lightroom to latest version following Keeping Lightroom Up-to-Date
If the problem persists then, refer the article Fix tethered shooting in Lightroom and follow the steps mentioned.
See A list of cameras that can be tethered to Lightroom. for reference.
I went through most of the Fix tethered shooting in Lightroom items. I had done the whole list in the past including firmware check on camera and trying another app to tether to. I was able to tether to the other app but still could not with LR. As stated, apparently my setup was not supported.
Yesterday I went through the Fix tethered shooting in Lightroom items again . Regarding number 8, there is a way to reset preferences using the Shift-Alt key combo when starting LR. That did not seem to work for me, but resetting them as described in #8 on the list seemed to work. I had also unplugged my wacom tablet and stopped charging my mouse via USB to see if that voodoo had any affect but I don't think it had. What seemed to have worked for me is a combination of
5. Put an empty memory card in the camera, especially if you're using a Nikon camera.
8. Reset Lightroom preferences.
and *start a new catalog just for the tethering.
*This wasn't listed in the Fix tethered shooting in Lightroom , but I read it somewhere and it seemed to work.
So hopefully I'll be able to go back and tether to an existing catalog but so far it seems stable.