I have a Nikon 5500. I also have a PC with Windows 7 (64bit) installed. Adobe states that Lightroom 6 can read the Nikon 5500 NEF files. I have the latest version of Lightroom and Photoshop CC 2015 installed on my PC and it can't read my NEF files. It says file is not recognised. Everything I have read suggests they should be able to be read / recognised. How can I get the Lr and Ps 2015 to read the RAW files?
Are you importing the images directly from SD Card or you have used any image transfer utility to copy the images to the desktop and then you importing it in Lightroom.
If yes, then take some random shots and import the images directly from SD Card.