Lightroom not showing photos in catalog, says its there when synchonizing

[Leone5C5C]

HELP!

I cannot find a single article describing what is happening to my Catalog right now.

I have lost photos in multiple folders ( At least three that I know of).

Photos, present on my hard drive, are not showing up in LR anymore (they did before). When trying to reimport them, they show as present in the catalog. I've tried to find them in other folders but they are in the right spot. I synchronized the catalog again,  nothing. 

I know I lost three photos I have worked on and saw missing but who knows how many more are gone.

Please tell me someone understands what could have happened.

[dj_paige · Accepted solution]

Lightroom Classic thinks the photos are in different folders than you think they are in. Probably, this happened because you (accidentally) imported photos using COPY or MOVE instead of ADD.

You need to find these photos in Lightroom. Follow all of these four steps in order:

1. In the Lightroom Library Module, on the left, under Catalog, click on All Photographs
2. Turn off all filters (Ctrl-L once or twice)
3. Turn off all stacking (Photo->Stacking->Expand All Stacks)
4. Search for at least one of these photos by file name using the Lightroom Filter Bar