sims 3 late night wont install

well my first problem is that every time i open up my sims 3 launcher it says there is a script error and i don't really know what that means, also when i go on to the game updates page on the sims 3 game launcher that i can not connect to the EA download manger which leads into my main problem of the fact the late night expansion pack wont install because when i select install it says installing below then a couple of seconds later it comes up with a message saying "please use The Sims 3 Launcher and update your version of the Sims 3 before installing this product which is really confusing me because this is not my first time installing this pack on to my computer and i have never really had a problem with it before, so could someone please help me out and telling me what to do and how to fix the problem that would be great thanks.