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#1
What I would try is to right-click an image file and click Open With and choose Paint, see if the file is actually viable. Personally I don't like the Photos program, prefer Windows Picture and Fax Viewer.
Those files have the suffix .jpeg instead of the usual .jpg. Check the .jpeg suffix is associated with the photo viewer you want to use. I just use the Photos app for quick viewing of all common photo types including .jpg and .jpeg.