PSE 23 Organizer Zoom View Not Working Correctly

Dear PSE Community,

I've just upgraded from PSE 18 to 23 and have spent most of the day importing my images into the new version.  However, I noticed once the import had completed that the zoom view within organizer does not work properly.  The grid view is fine and i can see all my images in each folder, but when i zoom in to max or double click on an image then i see a grey box with a question mark.  Any ideas what's going on here on how i might fix it?

Many thanks - Pete