Re: Sims 3 Launcher "There are no packages to install"
I was having this same problem but I figured it out! For me it turned out to be the new EA App. Go to settings in the upper left of the EA App.
Then go to "Application".
I changed two settings under here.
1: Under "Notifications", chose "none" from the dropdown list for "when I'm in a game".
2: Also disable the "in-game overlay".
The launcher should be able to uninstall/install sims3packs again!