Codes from the original City Life (2006) are not backwards compatible with the 2008 Edition. The 2008 release uses a different encryption seed. Attempting to use a legacy key will result in a "Invalid Serial Number" error.
The number 0 (zero) vs. letter O . The number 1 vs. letter I vs. letter l (lowercase L). Hyphens are mandatory. Capitalization does not matter (the installer converts to uppercase). City Life Edition 2008 Serial Code
Common examples found on original CD case stickers include: Codes from the original City Life (2006) are
Pro Tip: Ensure the listing explicitly says "Includes original CD key" or "Manual included." Many resellers separate discs from cases. City Life Edition 2008 Serial Code