Uninstall your most recent EP then download and reinstall the digital version from Origin. Instructions here.
I've moved your post to this stickied thread. Please read the instructions in the opening post link. You do not have to uninstall your entire game, just your most recent EP/SP. You also need to download and install the digital version of the 1.67 patch.
I'm trying to uninstall my most recent EP, University Life, as I was instructed to here, but just as I was starting the process, this message popped up: "You currently have one or more expansion packs for The Sims™ 3 installed. Uninstalling The Sims™ 3 University Life may cause those expansion pack(s) to no longer function correctly unless you update your game online via The Sims 3 Launcher. Do you wish to continue uninstalling The Sims™ 3 University Life?" Will uninstalling this expansion pack really damage my other EPs?
Don't start the game. Just uninstall it, download and install the digital version, download and install the digital patch if needed and away you go 🙂 You have to go into the hidden library folder and delete one folder that's left behind before you reinstall the digital EP. I've explained it in the guide so it should be easy to find.
Okay, thank you so much!
