In this tutorial - We will show article Why does the error occur "Unsupported Library"When we open a bookstore (Photos Library.photoslibrary) created by the application Photos developed by Apple for macOS.
Located in the folder /Users/username/Pictures
, library photo "Photos Library.photoslibrary"It's the best manager for storage, Editing and sorting pictures and video imported or made with iPhone. It is enough to have iCloud Photos Activated on the Photos application on Mac and iPhone, so that the pictures and video appear automatically on both devices. Or on other devices that you have the same iCloud account and activates Photos synchronization.
When we have two or more Mac devices, and the pictures are synconized on all, there is a situation that when we want to open the Photos bookstore, we will be greeted by the error: "Unsupported Library – The library “Photos Library.photoslibrary” Is from a newer version of Photos. Please upgrade Photos to open this library”

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Why does the "Unsupported Library" error appear when we want to open a photo bookstore (Photoslibrary) with Photos
"Photos Library.photoslibrary"It is a photo bookstore created by the Photos application. Apple developed by Apple, native on Macos, this are updated with the operating system.
We take the scenario in which we have two Mac devices and one of them has a newer version of macos.
Then When the photo library was created on Mac that has a newer maccos version, it is very possible that it cannot be opened on a Mac with an older version of macos. But be careful, this only happens when you save "offline"Booky photo (book .photoslibrary), for a External Hard or on another data support.
If we have, for example, we have a MacBook with Macos Catalina and another Mac with Macos Monterey, and both have iCloud Photos, there will be no problem in opening the Photos application. In the scenario in which the library "Photos Library.photoslibrary" was created on Macos Monterey, then copied on an external hard, will no longer be opened on Maccook with Macos Catalina, being created on a newer version.
Therefore, the library "Photos Library.photoslibrary" will not be open on a version of macos older than the one it was created. However, there is a possibility by which we can access the pictures and without opening the bookstore in the Photos application.
How we access the pictures from "Photos Library.photoslibrary" if the bookstore cannot be opened in the Photos application
If you encounter the "Unsupported Library" error when you want to open "Photos Library.photoslibrary" in Photos and you have no opportunity to update to the latest version, there is another option. You can physically open this bookstore and extract the pictures and video manually.
1. Right click on the "Photos Library.photoslibrary" file then click on "Show Package Contents"

2. We go to the folder ”originals
", Where we will find more folders with names from 0 9 and from A la Z. In these folders are all the pictures in .dng, .heic, .jpeg and video in .Mov format.

Unfortunately, they are not sorted into a relevant organ, but if you extract them all in a folder, you can use the sorting after the date, to put them in chronological order.
So you can never open the library with a less recent system?
I have hig sierra who does not read the photo bookcase on external disc created with Mojave 10.14.6
Is there no system? Without going from iCloud?