Re: Can't download anything from The Exchange? (Sims 3)
@emmafmhall It's good to keep the launcher open, as you're doing, but you might try selecting a different Sims 3 "app" to open the downloads. At different times, I've had to use the base game icon or the one for my newest pack by release date (University Life, in your case). Also try a different browser—Safari is known not to work well with the store. (The same is true of Chrome.) I use Firefox and have never had an issue.
If none of this helps, pull your entire TS3 game folder out of Documents and onto your desktop. Launch the game to create a new folder; there's no need to go farther than the Main Menu. Try downloading an Exchange file into this new folder. If it works, download the other stuff you want, and then move the downloaded files (in Downloads) from the new folder to the old one. Then trash the new folder and put the old one back, and you should be able to install your new content.