FrusturatedUser Does it ever help to only delete SigsCache? What about only repairing the game in the EA App (Sims 3 > Manage > Repair)? It's unfortunately not that uncommon to see Store content stop working, but usually a reinstall works for more than that one play session, so I wonder what's different about your setup.
Please also let me know whether you use any kind of cleaner app that might be deleting temp files.
Separately, try playing with your computer offline the second time you want to play after reinstalling the Store stuff. (You can sign into the EA App and put it into offline mode before disconnecting from the internet.) The idea here is to find out whether the problem happens when you connect and/or launch Sims 3 again, or before that.
