Instructions
Make sure your SD card is compatible with your Nintendo DSi gaming console. Your gaming console is compatible with most SD cards, as long as they are 32GB or less. They are also compatible with high-capacity SD cards (SDHC) up to 32GB in size.
Remove your SD card from the card slot on your gaming console if you receive the following error message:
"The SD Card is Locked."
Check the small slider on the side of your card. If it is in the "Lock" position, slide it to the "Unlocked" position to disable the locking mechanism.
Reinsert your SD card into the card slot. If you are using a compatible SD card and still running into errors. Contact Nintendo support because your gaming console may be faulty.