It’s possible that the videos are corrupted, but the “Unable to Share” message alone doesn’t confirm that. Since both your iPhone and iCloud storage are full, I would recommend checking the available storage and iCloud Photos settings first.
Here are a few things you can try:
- Free up some iPhone storage: Go to Settings > General > iPhone Storage and remove or offload apps or other content you no longer need. Avoid deleting the affected videos.
- Check iCloud Photos: Go to Settings > your name > iCloud > Photos. If Optimize iPhone Storage is enabled, the original videos may be stored in iCloud and may need to be downloaded before they can be shared.
- Check iCloud.com: Sign in at iCloud.com/photos and see whether the affected videos are available. If they are, try downloading them directly to your computer.
- Check the Photos app for sync issues: If iCloud Photos syncing is paused or incomplete, address the status message shown in Photos before attempting to transfer the videos again.
If the videos still cannot be played, downloaded, or shared after checking these items, the files may be damaged or there may be another issue preventing access.
Since these videos are important, avoid deleting them or turning off iCloud Photos until you have confirmed that you have a recoverable copy.
You can find more information in Apple's guides:
