How To Fix /IWBEP/CM_V4_MED252 - Return type kind of operation '&1' already set

SAP Error Message - Details

• Message type: E = Error

• Message class: /IWBEP/CM_V4_MED -

• Message number: 252

• Message text: Return type kind of operation '&1' already set

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message /IWBEP/CM_V4_MED252 - Return type kind of operation '&1' already set ?

  The SAP error message /IWBEP/CM_V4_MED252 indicates that there is an issue with the return type of an operation in an OData service. Specifically, it suggests that the return type for a particular operation has already been defined, and an attempt is being made to set it again, which is not allowed.
  Cause:
  
  Duplicate Return Type Definition: The error typically occurs when the return type for an OData operation (like a GET, POST, PUT, DELETE) is being set multiple times in the service definition.
  Incorrect Service Implementation: If the service implementation is trying to redefine the return type after it has already been set, this will trigger the error.
  Model Configuration Issues: There may be issues in the way the OData model is configured, leading to conflicts in return type definitions.
  
  Solution:
  
  Check the Service Definition: Review the OData service definition in the SAP Gateway Service Builder (transaction code SEGW). Ensure that each operation has a return type defined only once.
  Review the Implementation: Look at the implementation of the service methods (e.g., methods in the DPC class). Ensure that the return type is not being set multiple times for the same operation.
  Adjust the Model: If you are using a data model, check the model configuration to ensure that the return types are correctly defined and not conflicting.
  Regenerate the Service: If changes have been made, regenerate the service and re-activate it to ensure that the changes take effect.
  Check for Inheritance: If you are using inheritance in your OData service, ensure that the return types are not being inherited incorrectly, leading to multiple definitions.
  
  Related Information:
  
  Transaction Codes: Use transaction codes like SEGW (Service Builder) to manage OData services and SE80 (Object Navigator) to check the implementation.
  SAP Notes: Check for any relevant SAP Notes that might address known issues or provide patches related to this error.
  Debugging: If the issue persists, consider debugging the service to trace where the return type is being set and identify the root cause of the duplication.
  
  By following these steps, you should be able to resolve the error and ensure that your OData service operates correctly.