I upgraded Lightroom from the Creative Cloud last night - today I uploaded Sierra - and today nothing is communicating. I have a Nikon D600 - last week it was tethering perfect (for the most part) this weekend - with the changes - NO communication. Took my camera and connected to my laptop that is running El Capitan and the newest Lightroom and it is fine. There is some kind of a glitch in the compatibility - would love a solution. My Nikon D600 sure has had a rough run with Adobe the last couple years - not compatible for the longest time - then fixed - then this happens.