The "general decline of card" error can show up for a number of reasons, with the most common reasons being:

• Address, zip, or postal code mismatch
• Invalid CVV or expiration date
• Transaction timing out
• Insufficient funds
• Restrictions on the card itself such as fraud or risk detection

Double check the expiration date and billing address (some cards can be picky about things like "Street" vs "St", so always good to match exactly with the address on a bank/credit card statement); if you are still unable to get your payment to go through, please contact your banking institution.