Four images are not syncing properly in the Lightroom CC ecosystem. The images load fine with the originals on my desktop in Lightroom CC for Mac. They do download fine as Smart Previews to Lightroom CC for Mac on a second computer. Lightroom CC for Mac says the original is stored locally and backed up to the cloud. They are not loading in 3 different iOS devices, showing the message: “the photo failed to load.” Additionally, in Lightroom for Web, they do not show up, instead there is a placeholder and a message saying “Syncing file ___ from [my computer]. Added on 8/26/18.”They are all panoramas merged by Lightroom desktop, then re-imported to Lightroom CC. There was a batch of a dozen of them done and imported together. All are DNGs. They are big (one is 198 MP, 700 some MB), but I have yet bigger panoramas that sync fine. I’m only syncing Smart Previews to my iOS device.This seems to be a recurring issue with Lightroom CC. That is to say sync issues in general. I had problems earlier with Lightroom Classic someone making Lightroom CC that perfectly okay images were corrupted. (Without my even doing any editing in Lightroom Classic, just opening it again and not having turned off Sync.) I’ve since turned it off so that I can continue to merge panoramas and HDR photos.Note: This conversation was created from a reply on: Lightroom iOS: "the photo failed to load" on iOS after sync from Classic.