What cards password are you trying to enter? Not all Stardust Overdrive cards are in the game so you may be trying to enter the password for a card that is not in the game. Also, some Stardust Overdrive cards that are in the game cannot be gotten from using passwords like Majestic Star Dragon. --- Never assume anything, Assumption is the mother of all **** ups.
Okay the reason why most passwords are not granted because some of the real life cards or the cards in the website are not yet published in this game.
You might use the cards that involves mostly in Tag Force 4.
Use the previous passwords from the website that are accessible in Tag Force 4. Since Dark Tuner monsters for example are not in this game, maybe in the later Tag Force Series. --- Mostly Played: RM2 Continue Game+ -2nd Radiant Set Quest- Current Games: Tales of VS, Shin Megami Tensei Persona, Naruto Shippuden Legends, Akatsuki Rising