Re: [CURRENT ISSUE] Sims 3 Store content uninstalls/won't reinstall, EA App
For anyone still having this issue, if the steps listed by @EA_Cade don't completely resolve things:
The next step is to try playing in a clean user folder. Move the entire Sims 3 folder out of Documents > Electronic Arts and onto your desktop, and open the launcher to spawn a clean folder. This will remove all your saves and other user content, but it's all intact in the folder you've moved, and you can restore it later.
For now, please install one Sims 3 Store item into the new folder and make sure it stays installed through a restart of your computer. If it does, you can install the rest of your store content a few items at a time—the launcher doesn't handle large amounts of data very well. If everything stays installed, move your saves and any other data you want to keep to the new folder. Here's a description of the contents of the folder so you know what to transfer:
https://sims3.crinrict.com/en/2011/01/faq-user-files.html
Keep in mind that it's always better to let the game generate a new file or folder rather than resuing your old ones, so only transfer the files that contain data you'd otherwise lose, for example saves or saved builds.
