Restoring database failed

I made a backup copy of my Library folder, but when I went to open Calibre, it said that it needed to repair the database for some reason. (I use FreeFileSync for the backup)

I didn't fix it. I was able to open Calibre as Administrator, but then I can't add any books.

I tried moving the library to a new folder in Admin mode, but that didn't help.

Attached is the error box from the repair error box. I don't know why it has all those slashes in the directory structure.

Attached Thumbnails