Thanks Greg S.. I have Windows 10 and use Elements 13. Two years of images from January 2018 to January 2020 still appear but have the yellow ? question mark. I can't reconnect them. I hope you can help. Irene
If the files in your catalog became disconnected (which is what the yellow question mark means), there has to be a reason. Either they were deleted from your computer or they were moved or perhaps they were stored on an external drive that has changed it's assigned drive letter.
Does this provide any clues?
If the files remain on your computer, then you should do a search for them, using a Windows search for the file name. (Look for a file that has a yellow question mark in the Organizer.) If you find the files we can suggest how to reconnect them in the catalog.