Elements: Reconnect Missing Files

I named people by using the face recognition feature.
All images (several thousand of them) have the question icon in the thumbnail (they didn't before I did the naming of people).
I've added three new files, and they also cannot be displayed at maximum size - the software immediately starts searching for the missing file.

Something else that is confusing me, and may just have something to do with it, is the panel on the left. In tree view, Pictures is at the top, but when I click on it there is a message that no files have been imported. To see to the photos in my "Pictures" folder I have to go to /Volumes/Untitled/, then Users, then marionderrett, then Pictures.

 To see to the photos in my "Pictures" folder I have to go to /Volumes/Untitled/, then Users, then marionderrett, then Pictures.

I think here is the cause of your problem.
  

• Please tell us if you have a Windows (which OS?) or Mac (which OS?) computer.
• Advise which Photoshop Elements (PSE) version did you install.
• Also copy/paste the complete path of your "Pictures" folder.

In my computer (Windows 10) the complete path to my pictures folder is:

C:\Users\Jack\Pictures

The path can be found by opening (in Windows, I have no Mac) the explorer and navigating to the Pictures folder. Then in the field above the files and folders I see in my explorer: "> Jack > Pictures".
When I click on the empty space behind "Pictures" the path is selected and I can copy it to the clipboard.
Then check inside PSE the path that is displayed in the right panel under "Information" next to  Location  . If all is OK, this path should be identical to the path the Windows explorer used.

Please understand that PSE does not import your images into its database. It only saves the path to the original image that is stored on your computer drive(s). If there is anything wrong with the path, PSE will have problems that could be similar to your problem. 
 

I have a Mac, OS High Sierra (the latest). Photoshop Elements 2018.
I have found the path to my Pictures file: it is Macintosh HD/Users/marionderrett/pictures.
The PSE path is different - via /Volumes/Untitled/ This seems to be some sort of ghost folder, and may have something to do with my external backup drive.

I took a screenshot of what happens when I try to reconnect to the original photo in my Pictures folder. It seems to think it was originally in the /Volumes/Untitled/ folder. I cannot imagine how this happened!
I do understand that PSE does not import my images, but sees them on my computer.

Well, I'm pretty sure we have found the culprit. Now we have a few options to correct this problem.

1. Simply start a new catalog and import (now only from your hard disk!) all images again. That means you need to create new tags for your face recognition for all your images. This may seem a waste of time but might be the surest way of solving your current problem.
2. Delete all files from the PSE catalog and reimport them (again now only from your hard disk!). The difference from option 1. is minor. You don't have to create your face recognition tags again.

For option 3. we need to reconnect your external backup drive and check that PSE can find the images and no question mark remains in the upper corner of the thumbnails. PSE must recognize all images, otherwise you have to use option 1. or 2.
Furthermore you need to make sure you have all images backed up on your external drive! Now you must delete all (backed up) images in your Picture folder on your hard disk.
Rename your (empty) Pictures folder on your hard disk Pictures1.
Within PSE you go to the left panel and chose Folders. If all is OK you'll find all pictures in and under the Pictures folder.
Now you can move with your mouse the Pictures folder (it will automatically select all subfolders as well) from your external drive to your hard disk and preferably to your 'marionderrett' folder. PSE will start to copy all images from your external drive to your hard drive and will also delete them in the process. 
When finished, you need to make a new backup on your external drive of all your images.
Because many things can go wrong with the copy/move etc. process, it is wise to have a full backup on a second external drive! If this is not possible then seriously consider option 1 or 2....... 

As I mentioned before, I have no Mac computer (my last Mac was ditched 20 years ago...) so I cannot be entirely sure if you can rename the Picture folder and move a folder with subfolders named Pictures from an external drive to your folder on the hard drive. I hope you can, or know how to solve this problem using my information here above.
Wish you luck.....  

I don't think option 3. is for me! I have tried to find the images in my backup drive, but cannot do so. I also have only one external drive.

I would prefer option 2. to option 1. as I would be able to keep the face recognition tags. However, would you please tell me how to go about deleting all the files from the PSE catalog - I'm not sure of the best way to do this.

It is of concern to discover your backup is not OK. Are you sure the picture folder and all the files are not on your backup drive? They were there when you created the catalog.
But if PSE cannot find the pictures on your backup device then option 3 is indeed not possible.

For option 2 you simply select all files and delete them. I believe you use Option+A for selecting all files or items on a Mac. Do not select option to delete also from hard disk.

I spent much of yesterday trying to recconect to the external backup drive - I managed to find about 80% of the files, but couldn't get the rest. I then decided to give up and go with Option 2. I deleted all the files and reimported them however, when I did this I got back the same files in the same folder as I had before. I tried this several times, in different ways, but always with the same result.
I then noticed that the Get Media window has a box called Volume Name, and that the box is pre-filled with /Volumes/Untitled. It is greyed out, so I cannot change this.

It becomes obvious your backup external drive is still mounted (ghost drive). 
as I am not any,\more a Mac user, you must solve this problem yourself or with the help of knowledgeable Mac users.
I do not know why you cannot chose your standard hard drive for import of images, even if a ghost drive is present.

In a Windows OS, the get photos and videos command opens a standard Windows explorer window and I can chose any folder on any drive, internal or external:  

Many thanks for your help anyway - I'll let you know if I sort it out.

I couldn't find any help, although I did find that there have been problems with PSE and the latest Mac OS. I decided I'd got nothing to lose by making a new catalog and importing all my images again - your option 1.
This worked fine, and all the photos were where they should be. However, when I re-opened PSE again and it asked me to backup, I did so and immediately had the same problem as before!
I've now made a third catalog and am importing again. This time I will not do any backups.

No help I'm afraid as I have tried all these.

This may sound a little silly but it may help. If you are using a Windows PC and Edge as your default browser change it. Download (if you do not already have it) Chrome and make it your default browser and then see what happens. I know a few people who had problems getting their version of Elements to recognise RAW files and this turned out to be the answer.