You folks pulled me out of my last hole, and I hope you can do it again. System: Mac Mini, Version 11.1 Mac OS Big Sur LRC: Release 10.1
The problem was created via the following sequence: 1. Put two folders of photos in the wrong place in my hierarchy 2. I imported the photos 3. I realized they were in the wrong place and the photos belonged in a single folder 4. I created a single folder and put the photos in them. LRC would not import them. Hmmm. LRC clearly recognized it had dealt with this set before and was keeping me from duplicating. 5. Fine. I deleted the old folders on disk and removed them from LRC. No photos were lost, but I figured that getting rid of the old folders on disk and in LRC would be good enough. Not so, it seems. 6. Now LRC won't let me import them into the new location.
I figured the hole was big enough and I'd stop digging long enough to ask for help.
Importing never solves these types of problems. IMPORTANT RULE: Never re-import. You need to fix the photos, which most likely have an exclamation point icon, by pointing Lightroom Classic to the new location of the photos. http://www.computer-darkroom.com/lr2_find_folder/find-folder.htm Advice: stop organizing by moving photos and folders from here to there. Organize by keywords and other metadata, and you won't run into these problems.
Thanks for the link, and it was easy to fix my problem with the information in the link.
My fix process: 1. Select the year under which the problem folders/photos existed, which shows all photos in that year as you know. 2. Look for photos flagged with an exclamation point. 3. Click the exclamation point, which brings up a menu to locate the photo. 4. Point LRC to the photo in its new location. It pulled in all the photos from the first folder. 5. Repeat Step 4 for another photo. It pulled in all the photos from the second folder. 6. All is as I wanted it to be.
Thanks for the other tip. I will research the keyword tip a bit and see how I want to make it work.