Hi, not sure if this has been posted. When I convert a NEF file from the Nikon D750 to DNG using Lightroom some applications will not open the DNG, but the same file in its native format NEF can be opened. The files from my D300s when converted to DNG do open in other applications ....... perhaps that is a clue:)
This came from another forum............."Try using the adobe dng converter with the Compatibility set to Custom>Linear and see if that works"................and it worked!!!!!! Lightroom though does not allow for this.
None of the native apps on an updated Mac including the app Preview would open the DNG conversion.