Photos Library will not load back into Pictures

Hi Doug,

Based on this message I would say that this file is still on your iMac.

Did you try to open it? Here how to open it even it is moved to a different folder.

Switch between photo libraries Create additional photo libraries in Photos on Mac - Apple Support

1. If the Photos app  on your Mac is open, choose Photos > Quit Photos.
2. Hold down the Option key and double-click the Photos icon in the Applications folder (or click the Photos icon in the Dock) to open Photos.
3. In the Choose Library dialog, do one of the following:

• • Click the library you want to use, then click Choose Library.
  • If the library you want doesn’t appear in the Choose Library dialog, click Other Library, navigate to the location of the library, select it, then click Choose Library.

You wrote "I accidentally removed Photos Library from Pictures ..."

Did you delete the file? If yes you could check if it is still in the trashcan and restore it from there.

Did you move it to a different folder? If yes have you tried to move it back to picture folder?

Ralf