Unable to add photos to shared album from MacBook Pro

Hey richardchic,

First, we'd recommend checking for and installing any updates that may be available for your Mac to see if that helps as that can resolve compatibility issues when uploading to iCloud or resolve software issues with Photos thats built in to macOS: Update macOS on Mac - Apple Support

We'd also recommend reviewing this article as it provides steps to help resolve issues with the Photos app: Get help with the Photos app on your Mac - Apple Support

"If you're having other issues with Photos

If you're experiencing other issues—like missing or blank photo thumbnails, unexpected behavior, or if Photos won’t open—try to see if it's an issue with your library by following these steps.

Create a new Photos library and see if your issues persist:

1. Quit Photos.
2. Press and hold the Option key while you open Photos.
3. In the dialog that appears, click Create New.
4. Give your new library a name, then click OK. Note whether Photos opens successfully with this new library.

To return to your main Photos library, quit Photos. Then open it again while holding the Option key, select your main library, and click Choose Library.

Alternatively, you can open Photos in another user account on your Mac and note whether Photos opens successfully.

If Photos opens with the new library, or in a different user account, it might mean that there's an issue with your library. Follow the steps to use the Photos library repair tool on your main Photos library."

Thanks!