I have action to open in Photoshop that works fine with DNG no error.
However if from XnViewMP thumbnail view i drag file.dng to currently open Photoshop window then before opening file it displays this error message.

Moderators: helmut, XnTriq, xnview, Dreamer
Yes if i delete ExifTool backup files then i can drag and drop to photoshop from XnViewMP without any error messages.