October 2014
I'm not sure if this is a problem with my game or my computer, but I've never had this happen before. I believe I have four expansion packs installed now.
I just got a Sims 3 World Bundle with Monte Vista and Hidden Springs. I tried to install and everything went normally, and then I hit "Next" to start the installation. However, when I did that, the "finished installing" window popped up. The game was never installed. Anyone know what might be the issue here?
October 2014
As they are worlds, you can download them and install them that way.
To avoid any issues with the downloading - have your game launcher running at the same time as Origin before you download them.
Look here for more details about worlds: http://answers.ea.com/t5/The-Sims-3-Store/Guide-Sims-3-Store-Worlds/td-p/1589911