How to fix cannot load photo there was an error loading this photo on ipone and ipad in ios 14
You Have Enabled the Optimize Storage Option An enabled optimize storage option is one of the most common reasons why your photos are not loading in your device. With optimize storage options, your photos are saved on iCloud, thus you can only see thumbnails on your gallery.
How to repair buffering or loading photos or videos in your gallery || Muhammad Moosa
https://www.youtube.com/watch?v=eTAKM0mkY9M