Sims 3 DLC/Install issues

@beezwax319  The issue is probably that the existing Store content was corrupted, not uninstalled, and reinstalling with corrupted files present usually means the new install won't work either.  It's best to to start fresh with a new Sims 3 folder: move your entire folder out of Documents\Electronic Arts and onto your desktop, open the launcher to spawn a clean folder, download the store stuff again, install it, test, and then move your saves and other content to the new folder.

It's also best to install store items in small batches, no more than six or so at a time, as the launcher doesn't handle large amounts of data well.  Worlds should be handled separately, not in a batch with anything else.

If redownloading everything would be a chore, you can move the contents of Downloads from the old Sims 3 folder to the new one, and your new downloads should all show up.  For the rest, here's a list of everything in your user folder so you'll know what to transfer:

https://sims3.crinrict.com/en/2011/01/faq-user-files.html

It's always best to allow the game to regenerate files instead of copying them over; the only exception is options.ini if it would be annoying to have to reset all your in-game options.  If you have questions about a particular file or folder, just ask.