Sims 3 Launcher won't let me uninstall custom content

You usually get this message if you deleted a Sim from the savedSims folder instead of uninstalling them (or if the Sim didn't get properly installed in the first place). It means that the Sim shows in the launcher but it's not really installed to your game.

You can try this to remove the Sim from the launcher

1. Close the game and launcher
2. Go to documents\electronicarts\thesims3\savedSims
3. There's a file called downloadedsims.index (or something along these lines)
4. Move the file to the desktop
5. Start the launcher. The file should now be recreated and all invalid entries be removed. The Sim should no longer show in your launcher. 

Thank you for your reply. Unfortunately, that didn't work. Is the cc it came with supposed to be removed as well? Because when I tried that, the Sim was gone but the cc with it was still there. I should also add sometimes the Sim itself disappears completely from the installed content module, but some things it came with such as shoes and accessories are still there.

No, you will need to uninstall the stuff separately.

Do you get an error when uninstalling the cc too.

There are sims that don't install properly but the custom content that comes with them does, especially if you use save as and not add to game.