What is a 'payload error' in Salesforce and what are its common causes?

In Salesforce, a 'payload error' typically refers to an error that occurs when sending data (the payload) to Salesforce via an API call (like REST or SOAP). It signifies a problem with the data structure, data validation, or the API request itself. Common causes include: invalid data formats (e.g., incorrect date format), missing required fields, data exceeding field length limits, incorrect data types, and issues with API authentication or permissions. Debugging often involves examining the API request and response headers for error messages and specific details about the invalid payload.