400 Bad Request: Invalid Cross-Reference Key
Bad Data sent to API server
What does this mean?:
This happens when the field that is throwing the error was expecting a correct ID.
This means that the field was given a Salesforce ID, but the ID is not the correct object type or format. For example of the screenshot, the Record Type ID field was expecting a Salesforce ID of a record type, and not anything else such as an Account, Opportunities, or Leads.
Make sure you are mapping the right pill to the right field so that the Object ID matches with the expected type.