Thank you F. McLion. This seems to be my situation. My only question is how long is 'future'. Does this mean as soon as possible or do they mean wait till the next upgrade of Mac upgrade?????
Tethering with Nikon & Leica cameras
Tethering Nikon & Leica cameras using Lightroom CC 2015/Lightroom 6 is not currently supported on El Capitan.
We recommend customers who rely on Lightroom for tethering Nikon and Leica cameras not upgrade to El Capitan at this time.
Our engineering team is working with our partners to correct this issue and provide compatibility in the future.
As far as I know they are working on it, trying to fix it. When - in terms of days, weeks.. - no-one knows and they won't tell.