I have over 60,000 images on an external hard drive. Today when I opened Lightroom and tried to navigate to a recent image using the Navigator Panel, the folders and subfolders are all showing the numbers of photos inside the folder, but when I click on a subfolder it says "No photos in the selected Folder". When I check the Finder they are there. If I go to the highest level of parent folder on that external drive all 60,000 images are showing at that level and I can scroll through them. But when I drill down to any lower level that the very highest, they are not there. I have not done any moving of files or folders in the last several months and up until today everything was working fine. I have not installed any new plugins or done anything out of the ordinary with Lightroom recently. Any idea why this is happening and more importantly how I can fix it? I've included a couple of screenshots to show what I'm talking about.