I have read in many places about Sims 3 players having issues with disappearing Sims 3 Store and custom content. It seems to uninstall itself.
It's not only Steam and Origin players mentioning this, on a rare occassion I've read players with the disc version report disappearing store and custom content.
I haven't had any issues with disappearing content in quite some time, but still wanted to offer a suggestion of something that might help. -- Thinking of the disappearing content being due to Sims 3 not being white listed in your antivirus software.
Here's the troubleshooting steps:
-- Using a new Sims 3 folder.
Rename your current Sims 3 folder, so game can create new one when game is launched.
1. Disable the the antivirus software.
2. Install Riverview
3. Play Sims 3 in that open and close it a few times to see what stays installed.
If RV stays installed then it might be that Sims 3 may need to be white listed on your antivirus software. If you're not sure how, you may need to Google how to do that. As each antivirus software seems to have it's own way of doing things.
✽ If the above doesn't help you might try these tips from
this post.