Ever since I upgraded to version 10.0 of LR Classic, I am getting this error "An internal error has occurred: ?:0: attempt to compare two nil values" when I try to add some images to a collection. Now this doesn't happen every time but enough now that it's becomming a real pain. My only solution that I can find so far is to create a new collection, add the images to the new collection, move the images in the exising collection to the new one and then delete the old collection. I had never had this issue until i recently upgraded. Any help please?