Instructions
Remove the game you are trying to play from your Nintendo DSi. Leave the Action Replay connected to your console. Turn off your Nintendo DSi.
Turn your Nintendo DSi back on to access the Action Replay's main menu.
Select "Codes" from the main menu.
Highlight the code you were trying to use when your Nintendo DSi froze. Press the "X" button to open a sub-menu on screen.
Select "Edit" to view the code. Verify that you have entered the code into the Action Replay properly. If you enter a code incorrectly it can cause your DSi to freeze when you try to activate the code. If you entered the code incorrectly, make the changes using the buttons on your DSi.
Select "Delete" to delete the code from the Action Replay's memory. Certain codes attempt to change too much about a particular game and in turn can cause the game to freeze. In the event that this happens the only recourse is to delete the code and play the game without it.