I usually "add" photos to my lightroom library via an external hard drive. the photos are linked and not imported into a new lightroom library. today, I open lightroom (after the external has been unplugged), and it no longer recognized the external drive! catalogues and albums based on thousands and thousands and thousands of photos, nowhere to be found. any idea why this is happening or what I can do??? I'm afraid of reimporting the photos as I fear this will make me lose all my edits, cataloguing, etc. what do i do?!?