iPhone Photos shown on preview but gray when opened On my iPhone SE, some (but not all) of my recent photos will display their preview within the Photos app, but when I click on a photo it just shows a gray box. On some photos, a single line of pixels will appear on the top or the right side.

The images that are affected by this are unable to be uploaded onto iCloud or onto an alternative cloud storage service, and cannot be sent to someone else via any method.

I feel as if these files are corrupted, but have no idea how or why. Any advice on how to fix this issue or recover these photos?
I used to have this problem too. Quickest fix for me was to preview the photos one by one and open the editor for each one. I didn't have to do any fixing per se. After I saved them they appeared in the photos app normally. It was simple fix for me.