ERR_PAYMENT_METHOD on Stripe: Payment method invalid. Root cause: The payment method associated with this transaction is no longer valid. The card may have expired, the bank account details may have changed, the payment method may have been removed from the account, or the payment processor may no longer support the payment method type. Step 1: Check payment method. Verify method is valid Step 2: Check expiration. Verify not expired Step 3: Add new method. Register new payment method Step 4: Retry payment. Attempt payment again