How To Fix TN004 - Invalid WHEN parameter in function module

SAP Error Message - Details

• Message type: E = Error

• Message class: TN - Support Package Manager (SPAM) Messages

• Message number: 004

• Message text: Invalid WHEN parameter in function module

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message TN004 - Invalid WHEN parameter in function module ?

  The SAP error message TN004, which states "Invalid WHEN parameter in function module," typically occurs in the context of using the WHEN statement in a function module or a report. This error indicates that the WHEN parameter provided does not match any of the expected values or conditions defined in the function module.
  Causes:
  
  Incorrect Parameter Value: The value passed to the WHEN parameter does not match any of the predefined cases in the function module.
  Data Type Mismatch: The data type of the parameter being passed may not be compatible with what the function module expects.
  Missing or Incorrect Logic: The logic defined in the function module may not account for the value being passed, leading to an invalid condition.
  Configuration Issues: If the function module relies on configuration settings, any discrepancies in those settings could lead to this error.
  
  Solutions:
  
  Check Parameter Values: Review the values being passed to the WHEN parameter. Ensure they are valid and match the expected values defined in the function module.
  Review Function Module Logic: Examine the logic within the function module to ensure that all possible values for the WHEN parameter are handled correctly.
  Data Type Verification: Ensure that the data type of the parameter being passed matches the expected data type in the function module.
  Debugging: Use the SAP debugger to step through the function module and identify where the error occurs. This can help pinpoint the exact condition that is causing the issue.
  Consult Documentation: Refer to the SAP documentation for the specific function module to understand the expected parameters and their valid values.
  Check Configuration: If the function module relies on configuration settings, verify that these settings are correctly defined and active.
  
  Related Information:
  
  Function Module Documentation: Each function module in SAP has associated documentation that outlines its parameters, expected values, and usage. Reviewing this documentation can provide insights into the correct usage of the WHEN parameter.
  SAP Notes: Check SAP Notes for any known issues or patches related to the specific function module you are using. Sometimes, SAP releases notes that address specific errors or provide guidance on resolving them.
  Community Forums: SAP Community and other forums can be valuable resources for finding similar issues faced by other users and the solutions they implemented.
  
  If the problem persists after trying the above solutions, consider reaching out to your SAP support team or consulting with an SAP expert for further assistance.