Re: Late Night won't install??

see if crinrict marked solved post can help you http://answers.ea.com/t5/The-Sims-3/Sims-3-Late-Night-Wont-Install/m-p/1506475/highlight/true#M82399

if it doesn't help you, could you please state your operating system and how you bought the game (download through Origin or steam or DVD)