A serious bug in the iOS 15 Messages app can cause some saved photos to be deleted, according to multiple complaints we've heard from MacRumors readers and Twitter users.

If you save a photo from a Messages thread and then go on to delete that thread, the next time an iCloud Backup is performed, the photo will disappear.

Even though the image is saved to your personal iCloud Photo Library, it appears to still be linked to the Messages app in ‌iOS 15‌, and saving it does not persist through the deletion of the thread and an ‌iCloud‌ backup.

To replicate this bug, the following steps must be taken:

1. Save a photo from a Messages conversation to your Camera Roll.
2. Check to see that the photo has been saved.
3. Delete the Messages conversation the photo came from. The photo will still be in your ‌iCloud Photo Library‌ at this point.
4. Perform an ‌iCloud‌ Backup, and the photo disappears.

This is a concern because most users keep the ‌iCloud‌ Backup feature enabled and it's something that happens automatically. If you're someone who regularly deletes message threads, if there's a photo that you want to keep, you won't be able to keep it with ‌iCloud‌ Backup turned on. We tested this bug on an iPhone running iOS 15.1 beta 2 and had our photo deleted after deleting the Messages thread and performing an ‌iCloud‌ Backup, so the issue has not been addressed in the current beta as of yet.

Until this bug is fixed, if you've downloaded photos from the Messages app, you'll want to make sure to keep those Messages conversations and not delete them to prevent them from being automatically removed from your devices