You do need to move your CC back when you do a factory reset. It's DCCache and ccmerged.package in DCBackup if your CC is in Sims3Packs, and the Mods folder if it's in packages.
I've never heard of it disabling EPs, though.
I would do a reinstall in that case. Make sure to move your Saves, Downloads, and everything else you want to save to a safe location before doing that.