How To Fix SPXN191 - Signature is incompatible (parameter mismatch)

SAP Error Message - Details

• Message type: E = Error

• Message class: SPXN - Proxy Generation

• Message number: 191

• Message text: Signature is incompatible (parameter mismatch)

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message SPXN191 - Signature is incompatible (parameter mismatch) ?

  The SAP error message SPXN191, which states "Signature is incompatible (parameter mismatch)," typically occurs in the context of function modules or methods in ABAP when there is a mismatch between the expected parameters and the actual parameters being passed. This can happen in various scenarios, such as when calling a function module, method, or when using RFC (Remote Function Call).
  Causes:
  
  
  Parameter Mismatch: The most common cause is that the parameters defined in the function module or method signature do not match the parameters being passed. This can include:
  
  Incorrect data types (e.g., passing a string where an integer is expected).
  Missing required parameters.
  Extra parameters that are not defined in the function module or method.
  
  
  
  Changes in Function Module/Method Signature: If the function module or method has been changed (e.g., parameters added or removed) and the calling program has not been updated accordingly, this error can occur.
  
  
  Version Mismatch: If you are calling a function module or method from a different version of the system or from a different system where the signature has changed, this can lead to incompatibility.
  
  
  Solutions:
  
  
  Check Parameter Definitions: Review the function module or method signature in the ABAP Dictionary (SE37 for function modules, SE80 for methods) to ensure that the parameters you are passing match the expected parameters in terms of type, number, and order.
  
  
  Update Calling Code: If the function module or method has been modified, update the calling code to match the new signature. Ensure that all required parameters are provided and that no extra parameters are being passed.
  
  
  Use Consistent Versions: If you are working in a multi-system landscape, ensure that the same version of the function module or method is being used across systems. If there are discrepancies, consider synchronizing the versions.
  
  
  Debugging: Use the ABAP debugger to step through the code and inspect the parameters being passed to the function module or method. This can help identify where the mismatch is occurring.
  
  
  Documentation: Refer to the SAP documentation or the function module's documentation to understand the expected parameters and their types.
  
  
  Related Information:
  
  
  Transaction Codes: 
  
  SE37: Function Module Maintenance
  SE80: Object Navigator (for classes and methods)
  SE11: Data Dictionary (to check data types)
  
  
  
  ABAP Development: Familiarity with ABAP programming and understanding of how function modules and methods work is essential for troubleshooting this error.
  
  
  SAP Notes: Check SAP Notes for any known issues or updates related to the specific function module or method you are using.
  
  
  By following these steps, you should be able to identify and resolve the cause of the SPXN191 error in your SAP environment.