I bought the PHYSICAL CARTAGE of Tomodachi Life, and I gave an extra code to a friend who does NOT have TDL, and when she put it in, it failed. It wasn't used, it was out-of-the-box, so the error was it was inputted incorrectly, but I'm sure I did it right! I also used the rule with not using certain letters, STILL annoyed. Please help!
EDIT: forgot to say I tried that code multiple times, also. No luck.