The WEP key for the Access Point you are attempting to connect to has changed since you last connected.
Verify the Access Point's WEP Key is entered correctly into the Nintendo DS. If your router has slots for more than one WEP key, the first (#1) must be the one selected on your router. If you need assistance, click here and select your router manufacturer and model number. If available, our router pages can provide specific steps and information that may help you with your router's WEP Key.
If you have multiple connection files saved to your Nintendo DS, the error message you received can help determine which connection file may be experiencing a problem:
If the above information does not work, and you are connecting at home with a wireless router, there could be settings on your router that need to be adjusted. Please click here for more information.