Issue with my mods

Hey! So, here lately, everytime I download a new mod it's just- won't show up. It doesn't show up in game or in the starting pop-up. I always make sure the files are unzipped, in the right mods folder, and have been updated for the newest updates, but still nothing Is it because I've got broken CC in there somewhere or something?? Any tips, advice, and solutions to fix it are greatly appreciated, thanks! (Extra notes; I play on PC and download mods from a variety of places, but I always make sure they're safe)