Something has happened. If I shoot in RAW, I can preview the image in the camera but when I go to download, I can't see the file. Thus I can't download it. So I am now shooting all JPEGS. This problem applies to both of my computers.
One operational fact is that I now reformat the card to erase images after downloading. This gets rid of the accumulating subfolders that the camera creates.
Anyone have advice on what is happening?