I have just upgraded to Lightroom 6 and when importing photos get the message, "files not recognised by raw format in Lightroom". Camera is Nikon D 5
If you have just upgraded to Lightroom 6 then you probably have Lightroom 6 .0. Your camera requires at least Lightroom 6 .5. Go to the help menu in Lightroom and click on updates and make sure you are up to date. The latest version of Lightroom 6 is version 6.10.1. After you get Lightroom updated you should have support for your camera.