Photoshop Can't Find Lightroom Photos

See: https://community.adobe.com/t5/photoshop/how-to-link-lightroom-library-to-photoshop/td-p/9485638?page=1

Your image files are not in Lightroom they are in folders on your computer's HDD, external HDD or network drive. If you wish to open them directly using Photoshop you need to access them in your folder structure, or alternatively use Lightroom to "Edit in Photoshop", as advised by Just Shoot Me in the first reply in this thread.

Do Photoshop and Lightroom have access permissions to the catalog folder and the images folder?

I have moved your post from the poorly named Community help forum to the LR Classic forum which you say you are using.

But then you say "When I try to access/load LR files from PS". You do not access LR files from PS. In LR Classic you Send images From LR to Open In PS, "Edit In > PS".

So I have no idea what you are actually trying to do.

Then you say "I get a message that your LR library is empty".

Please post a screen shot of the Full LR Classic user interface you are seeing on your screen.

If the Library module is not showing any images then one of 2 things is going on.

1) You have a Filter set that no images correspond to. You are actually Filtering out all your images.

2) You have opened a New Blank Catalog file and have not imported any images into that catalog.