Clips captured using capture now often come out called “Untitled1”, “Untitled2”, “Untitled3” etc. And the tape name if not specified is “001”. A lot of people have a habit of sticking a tape, opening L & C and doing capture now without specifying any names. And without saving the project first. So the folder in Capture scratch is called “Untitled Project 1”.
They then rename clips in FCP, but outside FCP the Quicktime files are still called “Untitled1”, “Untitled2”, “Untitled3” etc. And stored in folders called “Untitled Project 1”, “Untitled Project 2” etc. Over time, there are tonnes of clips with the same names this way and FCP gets confused.
The other thing is folder paths. It is not uncommon to see Capture Scratch at the root of a drive and one inside a folder called “Final Cut Pro documents”. And some at other locations as people often specify other paths for scratch disk.
So search all your drives for “Untitled” and for “Capture Scratch” and folders by the same name as the current project media folder. If you find more than one of these, then that is your problem.
Neil