How to Fix Mac Photo Gallery Backup on Damaged External Hard Drive

A long time ago, I directly dragged the Mac's photo library to another hard drive for a backup, that is, the following photoslibrary file ! [72mdcoHAZ3wgs6L] (https://s2.loli.net/2025/05/05/72mdcoHAZ3wgs6L. png) But when opening today it shows the following message ! [PJYBjzR2kEsvKbD] (https://s2.loli.net/2025/05/05/PJYBjzR2kEsvKbD. png) Looking for relevant information online, the only way to teach you how to fix the default photo gallery is to hold down option + command and then press the photo app above dock: ["Photos" cannot open the gallery "photoslibrary.photoslibrary". (4103) How to solve it] (https://discussionschinese.apple.com/thread/251916817?sortBy = rank) This method can only repair * * the gallery currently opened by the photo app * * My idea is to set the photos app's gallery as backup gallery first and then fix it, but this doesn't work for the following reasons: First hold down option and then click on the photo app above docker, try to select the gallery ! [UEIKwHpL1O4J8BV] (https://s2.loli.net/2025/05/05/UEIKwHpL1O4J8BV. png) However after opening it shows this: ! [eTYQu3fJ9DdSijB] (https://s2.loli.net/2025/05/05/eTYQu3fJ9DdSijB. png) In other words, * * I can't make the default gallery of the current photo app my backup gallery * *, so naturally I can't use the method of holding down option + command and then pressing the photo app on the dock found online However, the backup.photoslibrary file, the photos that exist inside (click "show package contents") are fine: ! [PW6YpTU1qo3cOBD] (https://s2.loli.net/2025/05/05/PW6YpTU1qo3cOBD. png)