Cannot right click, delete, or see file name of thumbnails in Library

[allainc53579028]

I am using Lightroom Classic 9.3 Release. There is a group of images that don't seem to be connected to files, nor can they be deleted/removed. Selecting individually or as a group, I cannot right click, nothing happens with Photo(Menu)-Remove Photo, or I cannot see file names in Metadata to connect these files to anything. 

I am using a Mac and all other photos in my Library are acting as expected.

Looking for help to get these thumbnails out of my Library. Thank you!

[GoldingD]

 See: https://helpx.adobe.com/lightroom-classic/kb/photos-appear-black-gray-rectangles.html

[Rob_Cullen]

You have more problems than just the 'Grey' thumbnails!

You also have many thumbnails that show as "Missing", meaning that the catalog is not connected with the original image files.

Show us a screen-clip of your Folder panel- opened to show folders.

Is your Drive with image files connected and showing the 'Green' light in the Folder panel?

After the "Missing" Folders and files have been re-connected, You may be able to delete the Previws cache and let it re-build. PREVIEW CACHE ERRORS