Root Cause

• Incorrect request parameters: The required fields are missing, invalid, or in an invalid format in the API or payment request.
• Unsupported payment method or transaction type: The request attempted to use a payment method or transaction feature not supported by the gateway.
• Invalid resource identifiers: The request referenced an incorrect identifier (e.g., invalid customer ID, payment method ID).
• Malformed API request: The structure of the API call does not match the expected schema defined by the payment gateway.

Troubleshooting and Solutions

• Review the API documentation or integration guidelines to ensure all required parameters are correctly included and properly formatted.
• Check if all the required parameters are being collected during the checkout process and passed on to Chargebee or the payment gateway.
• Contact Chargebee Support if you need to validate this within Chargebee's integration with the payment gateways.