I suspect you are loaded filters into your FCP filters folder.
I am confused. Are the files for Pro Tools that you have tried to load into FCP for use while editing?
To delete these files from the plug in's folder, Open a Finder window, go into your Home folder, then go into your Library. From there scroll down and find a folder that says Preferences. Open that folder, it's much easier to view it in List view to find the FCP folder. Make your way to the folder that says "Final Cut Pro User Data" you'll see the Plug ins folder. Drag them into the trash and empty the trash.
It may be easier to open FCP and see what you need to delete.
Correct me if I didn't full understand your question.
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