While downloading Sims 3 Late Night I receive error of invalid code

While downloading The Sims 3 Late Night, every time I enter in the registration code I receive the error: "You have entered an invalid code. Please check that you entered the code correctly."  I have tried everything, with caps lock on with caps lock off and even taking my computer off my wifi. This is an old game of mine that was previously downloaded on another computer that I no longer have access to, I don't know if that could be affecting it. What can I do to get this expansion downloaded? This is the first expansion I have tried to download since I re-downloaded the Sims 3. If it helps I'm downloading by disk.