Files are disappearing

If everything works now, that's great.

But Lightroom Classic is saying you have two copies of this photo, not me.

I think the link between LR and files is breaking. I seem to be getting an increasing number of images stating the original file cannot be found. When I attempt to relink it I'm told that the file is "associated with another photo in the catalog. Each file can only be associated with one photo."

This usually happens because you have imported the same photo into LrC twice (and one time imported using COPY and the other time imported using ADD). To determine if this is the correct explanation, please search for one of these photos in LrC by following all four of these steps:

1. In the LrC Library Module: Click on All Photographs (on the left under Catalog)
2. In the LrC Library Module: turn off Filters (Ctrl-L once or twice)
3. In the LrC Library Module: Expand all stacks (Photo->Stacking->Expand All Stacks)
4. In the LrC Library Module: use the filter bar and search for one of these photos by file name

Do you find two (or more) copies of this photo?