Error while installing worlds

RexyStorms​  The Sims 3 launcher doesn't handle large amounts of data very well.  Trying to install multiple worlds at once counts as a large amount of data.  I don't know whether you did that the first time too, but it's possible you broke the Store installed content, in which case reinstalling it isn't going to fix it.  Instead, please install the content into a clean folder, as described here:

[Read First] Sims 3 Store guide | EA Forums - 11157679

You can move your saves and other content to the new folder once you're done.