The character creator is essentially a port of the in-game creator and as long as it is updated along with the game, all codes should work 100% of the time. The issue, as Mizuki mentioned, is that it is not a big priority to update the website character creator. In addition, as we develop the game further, it is inevitable that your codes will become invalid since the internal structure of the pony data will be changing. We apologize ahead of time, but it is a necessary eventuality. Development must move on!
I am now closing this topic since the original question has been answered.