CC not showing up!!

Hi! I've been trying for ages now to get some cc into my game. I have The Sims 2 Ultimate Collection. I saved the package files into \Documents\EA Games\The Sims™ 2 Ultimate Collection\Downloads. I also checked all the boxes in the game that were needed, and still nothing shows up! It's as if I haven't done anything. That box that's supposed to appear when i start the game doesn't pop up, and if I open it manually it's blank. I have CC in The Sims 4, so I have a general idea of how it works. Am I missing something here?