I had a Hard Disc Failure, bought a new Mac (it was time), placed all my photos on an External Drive in a File Called 'Pictures', and downloaded Lightroom Classic from Adobe. I placed a B/U lrcat Catalogue file in Pictures/Lightroom and instructed LR to open that Catalogue, which it did. In LR I can see over 10 years of photos in their appropriate folders, with the correct number of photos in each folder however no previews are visible in the Grid (or Loupe) views. When I try to link a photo or folder to the new photo or folder location on the External Drive, not only does it not link but the photo or Folder immediately disappears from the LR Folder list! It then shows the Name of the Folder followed by Zero photos. I tried using a different B/U catalogue, moving some pictures off the External Drive to the Mac - to see if they would link - but no luck. It would appear that I have a Catalogue with >10 years of work editing and I would hate to go the route of importing all the pictures and having to edit all of them all over again. Any advice would be hugely appreciated.
When I try to link a photo or folder to the new photo or folder location on the External Drive, not only does it not link but the photo or Folder immediately disappears from the LR Folder list!
This indicates success. The folder has disappeared from the list because it has been replaced by the new folder location, and your photos in that folder are now not missing. Look for the new folder location.
Wow! You're right! It's not obvious because the folders disappear from "MacIntosh HD" and appear under "Extreme Pro" because (Duh!) that's where they now are. I still have a problem with one folder not showing up in the right place but the others seem to locate and link perfectly. I can't thank you enough - I thought I was going to have to shoot myself.