If this error appears, the credit card you have registered on your account may have expired. You can register and check your credit card from Settings > Account Management > Account Information > Wallet > Payment Methods:
- Check the expiration date of your credit card and register a valid credit card.
- If there is no problem with the expiration date, please double-check that the registration information such as the credit card number is correct.
- Delete the currently registered credit card and register again.
- If possible, register another credit card and check if it can be used.
- This may be a temporary issue. Please use another payment method, or wait 24 hours before attempting to add payment information.
Please note that payment operations will be temporarily unavailable if you register or delete your credit card multiple times in a short period. If this happens, please try again after 24 hours.