Was the file you edited already a .dng file? Or did you change the original file name from - say, xyz.jpg - to xyz.dng when saving? I may be wrong but if that's what you're doing I don't think it can work that way.
No... these are fresph off my Nikon D3100 in NEF .. I transfered them/moved them to my PC... I I onened them did some editing .. saved them (only save opten is a ,dng) and closed them... Tried to reopen them and they wont open... no error messages or anything just wont display
I'm not qualified to help you with this. Not my strong suit, hopefully someone jumps in here momentarily to help you out with it. But I'm curious, what happens if you change the file extension from .dng to .nef?