SAP Knowledge Base Article - Public

3082872 - Error: "GENERAL_ERROR Error during proxy processing (PART UNKNOWN (NULL))"


You receive error:"GENERAL_ERROR Error during proxy processing (PART UNKNOWN (NULL))", in external web service response even though they receive successful message in web service message monitoring payload response.


  • SAP Cloud for Customer
  • SAP Business ByDesign
  • SAP Cloud Application Studio

Reproducing the Issue

  1. Log in to frontend system.
  2. Go to the Communication Arrangements subview.
  3. Open the relevant communication arrangement 
  4. Note that the payload is triggered from the external system like CPI or ERP, however the SAP C4C or SAP ByDesign only receives response message and can be viewed here as Error:  "GENERAL_ERROR Error during proxy processing (PART UNKNOWN (NULL))"


  1. Open SOAP UI.
  2. Load the WSDL for the respective service to a new project.
  3. Select the operation and generate the request.
  4. Enter the request XML.
  5. Maintain the Authentication details.
  6. Execute and you get the error in the Results window with Error: "GENERAL_ERROR Error during proxy processing (PART UNKNOWN (NULL))"


The WSDL needs to have end point for the C4C in the response message payload.


The error could be resolved  after adding namespace "C4cCustomer" to the response message. Example sample as below.

<urn:CustomersReplicateResponse xmlns:urn="urn:C4cCustomer">


proxy processing (PART UNKNOWN (NULL), C4cCustomer, wsdl, response , KBA , AP-RC-BDS-WS , ByDesign Studio Web Services , How To


SAP Business ByDesign all versions ; SAP Cloud Applications Studio all versions ; SAP Cloud for Customer add-ins all versions