How can I fix the error when Photos can’t load the full-quality image?

Closing and reopening Photos is easy through the app switcher, but it generally won’t fix this particular message. Check both your phone and iCloud storage, along with your connection. You still have roughly 35 GB free on the phone and 24 GB in iCloud, so the most useful next step is verifying whether the full-size image is actually available online.

That message usually means your phone has only a smaller preview and is trying to download the original from iCloud. A slow or unreliable Wi-Fi connection can cause it, but the original may also have failed to upload in the first place. Check the same photo at iCloud.com/photos on a computer. If it opens at full resolution there, the problem is downloading it to your phone. If it doesn’t, the original may not have finished uploading. In Settings > Photos, check the sync status near the bottom, then leave the phone connected to Wi-Fi and a charger overnight. Also check whether Low Power Mode is pausing synchronization. Updated terms and conditions only matter if Settings is displaying a notice about them. Avoid resetting sync data until you confirm the original exists in iCloud, since doing so could remove local previews that may be your only remaining copy.