photos

If your search doesn’t succeed, you can create a new Photos library. To create a new Library, launch Photos while holding down the Option key. Starting this way will also list all Libraries that Photos can find on your system.

If you do create a new library, set its preferences as your System Photo Library and activate iCloud Photo Library. This will (slowly) download all your photos from iCloud Photo Library.

You need to find the Photos Library.photoslibrary file and then double-click on it. This will link it back to the Photos app.

The Photos Library file is normally in your user Home folder, in a Pictures sub-folder. You might have accidentally, or purposefully, moved it somewhere else, for example to an external drive.

Perform a Spotlight search for either Photos Library or photoslibrary.

Have you used the Photos app successfully on this computer before?

When you go to: Macintosh HD > Users > your name > Pictures folder, what files do you see there?

That’s good news! If you use iCloud Photo Library to sync them, then at least we know you haven’t lost any photos and we can bring them back to the MacBook if need be. But let’s figure out what happened to the Photos Library on the Mac first.

Can you please take a screenshot of that window and post it here.

Screenshot: Command+Shift+4, then the Space Bar, then click on the window.

To post it here click on the Picture icon in the toolbar of a new text reply box.

It’s the built-in indexing and search utility. Click on the magnifying glass icon in the main title bar.