My Apple/Aperure images were transferred to Lightroom seamlessly a couple of days ago, including Smart Previews.
Yesterday, I connected the relevant external drive but could not access my images, although thumbnails from Smart Previews are there.
The active drive’s name is APL 1TB.
But the active drive shown in the left hand Library panel has a “1” appended and reads APL 1TB1; and does not have a green light. And the files have ? marks. So it seems like a mistype happyened along the way.