Re: New Sims 3 expansion: says in-game content, can't install
@JamiyaM20 I've merged your post with the master thread for this issue. The only fix is to uninstall and reinstall the entire game, unfortunately.
If you have the space available on your computer, I'd suggest renaming the Sims 3 folder that contains the game's program files rather than uninstalling. (This is NOT the user folder in Documents > Electronic Arts, which contains saves and other user data.) Some players can't reinstall the game at all, but having a backup copy of the program files can help get around the issue. Make sure the EA App is closed and the EABackgroundService is NOT running in the Task Manager, then change the folder name to something that doesn't include "Sims 3."
Open the EA App and choose to install the game into a different folder than you used previously. If it works, you can delete the old Sims 3 folder you renamed and get the space back. If you run into a download error, close the App and kill the EABackgroundService, then copy the program files to the new location where you want to install Sims 3. When you try to install again, the App should simply verify the existing files rather than trying to redownload the data, and it will hopefully also download your new pack.