How To Remove A Piece of CC. . .

It causes unsightly black streaking on the Sim wearing it and a question mark. Which is really too bad, it's really a perfect dress for my Period-Save, set in the 18th century. (Perhaps merging with other cc is the surprise?)

I do have Sims 4 Studio, but I really need to learn just how to use it. Thanks. In the past I have emptied my Mods folder, entirely and placed the mods I need, one at a time. Recently, however, I've indulged in clothing cc and a few objects, as well. I came across a mod that would find and fix, but it hasn't been updated . . . 

Hi, I'm going to mark you as the solution.  I took all of the cc hair; accessories, and clothing and put that into the mods folder. I removed them one at a time, then tested. Felicity's Surprise was still showing up. This testing was done by folders, as that's how I have my Mods folder organized. When I got down to the cc Hair, I opened that file and slowly went through the names of each piece of cc. I'll be darned if I didn't find Felicity's Surprise. package.  Happily, not merged with another piece of cc, but how it got out of the Girls dresses file, is beyond me. Phew! It is now out of my game. YAY. Thank you again.