Folder are gone!

Hey guys,

I have now already purchased this plugin in the Pro version for several pages of our group. Unfortunately, problems occur more and more. Now we have already uploaded and categorized hundreds of files on one site and suddenly the folders are no longer visible.

But they are still there: Because when I create folders with the same name, they are numbered (this speaks for the fact that the designation already exists). Do any of you have a tip on how I can fix this?