1. Mac Screensaver Photo Library Missing
2. Mac Screensaver Photo Library Missing Image
3. Best Screensavers For Mac

Photos in your System Photo Library are available in apps like iMovie, Pages, and Keynote. You can also sync them to iOS devices and view them on Apple TV. And if you want to use your own images as your desktop picture or screen saver, the images need to be in your System Photo Library before you can select them in System Preferences.

The Media Browser shows only photos that have the original image or a full-size preview stored on your Mac. To make a photo temporarily available to the Media Browser, double-click it. This downloads the original to your Mac, where it's available in the Media Browser until Photos optimizes it again to save disk space. The Mac Photos app works well for most users, but occasionally a variety of hiccups can be encountered when interacting with photo libraries, ranging from crashes, to hanging on Photos app launch, a failed import, thumbnails missing from an image library, pictures missing from a library that was imported, or even a completely empty Photos app.

If you have only one photo library, then it's the System Photo Library. Otherwise, the first photo library that you create or open in Photos will become the System Photo Library. If you have more than one library, you might need to designate a System Photo Library, so other apps can access the photos and videos you want them to use.

Follow these steps to designate a System Photo Library:

1. Quit Photos.
2. Hold down the Option key and open Photos. One of the photo libraries is already designated as YourLibraryName (System Photo Library).
3. Choose the library you want to designate as the System Photo Library.
4. After Photos opens the library, choose Photos > Preferences from the menu bar.
5. Click the General tab.
6. Click the Use as System Photo Library button.
   

If you open a second or different library in the Photos app, and you haven't designated it as the System Photo Library, other applications will use photos from the original System Photo Library. Hold down the Option key when you open Photos to see which library is set as the System Photo Library.

iCloud and the System Photo Library

You can use iCloud Photos, Shared Albums, and My Photo Stream only with the System Photo Library. If you choose a different library in Photos without designating it as the System Photo Library, the iCloud tab in Photos preferences is disabled:

If you designate a new library as the System Photo Library and then turn on iCloud Photos, the photos and videos in the new library will merge with those already in your iCloud Photos. If you want to keep the contents of your photo libraries separate, don’t turn on iCloud Photos for more than one library in Photos.

Mac Screensaver Photo Library Missing

This happens when you use iCloud Photos with the Optimize Mac Storage preference enabled.

The Media Browser shows only photos that have the original image or a full-size preview stored on your Mac. To make a photo temporarily available to the Media Browser, double-click it. This downloads the original to your Mac, where it's available in the Media Browser until Photos optimizes it again to save disk space.

If you want to make pictures in Photos permanently available in the Media Browser, follow these steps:

1. Select File > New Album from the Photos menu bar. Give the new album a name.
2. Control-click (or right-click) the pictures that you want to make available in the Media Browser. Choose 'Add to [new album].' Or drag the pictures to the new album.
3. Find the new album you created.
4. Control-click (or right-click) the album and select Download Originals to this Mac.

This downloads the full-resolution version of the pictures you selected to your Mac and makes them permanently available in the Media Browser.

Mac Screensaver Photo Library Missing Image

Best Screensavers For Mac

If you want to make all the pictures in your Photos library permanently available to the Media Browser, you can select Download Originals to this Mac in the iCloud tab in Photos preferences. When you do this, you'll lose the space-saving benefits of the Optimize Mac Storage preference.