@beccahimes
If you open the Uninstaller in Applications > Electronic Arts > The Sims 3 do you get the option to uninstall Ambitions? If so please uninstall it and also follow these instructions for a manual uninstall of the hidden Library files left behind. If it is not available through the uninstaller then follow the instructions and manually uninstall it. Now patch your game to 1.67 again using the manual patch (link in my signature below), then attempt to reinstall Ambitions from the disc. If it still isn't working then I would recommend registering your product codes in Origin and downloading and playing the digital version.
It may be a good idea to edit the info.plist file back to its original state so you are not bypassing the Launcher, just until you've managed to successfully install Ambitions 🙂