I have the same problem, and was just googling about it.
It appears to be a bug with Windows 10, and on the Microsoft forum they have acknowledged this and said that they are working on a fix.
In the meantime, one solution appears to be to remove the card from the camera and to use an SD card reader. That should show you the files.
Another solution, easier if you do not have a card reader hanging around, is to download Nikon's View NX 2 software, then connect the camera as normal via USB. This can copy images from the camera to a folder of your choice, and it works fine even in Windows 10. This is what I did.
Regards
Mark
08-19-2015 11:10 AM