Installation issues, incompatible version!

I bought Showtime ep, but whenever I'm installing it it says "The Sims 3 version is more recent than expected, The Sims 3 Showtime could be incompatible. Make shure you get all the updates before pleying". So whenever I click on the Showtime icon it starts the launcher but doesn't play the Showtime ep, it plays the last ep I installed and it shows as if it was never installed. I have my game updates up to date.