Restoring photos from Time Machine
If you have a Photos library that has either become corrupt or had photos accidentally deleted from it, and you have been using Time Machine to back up your library, you can restore a copy of your older library to access those photos again. You can restore your library by following the instructions on Apple’s Restore items backed up by Time Machine support page. Once the library has been restored, add the library to PowerPhotos’ library list. The library will need to be opened once in Photos to allow it to complete the restoration process before PowerPhotos will be able to display the library’s content in its own window.