How To Fix CPF121 - Parameter &1 must be a custom field. Prefix &2 is required.

SAP Error Message - Details

• Message type: E = Error

• Message class: CPF -

• Message number: 121

• Message text: Parameter &1 must be a custom field. Prefix &2 is required.

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message CPF121 - Parameter &1 must be a custom field. Prefix &2 is required. ?

  The SAP error message CPF121 indicates that a parameter being used in a function or program is expected to be a custom field, but it is not. This error typically arises in the context of ABAP programming or when working with custom enhancements in SAP.
  Cause:
  
  Incorrect Parameter Type: The parameter being passed does not match the expected type. The system expects a custom field, but the provided parameter is either a standard field or an incorrect data type.
  Missing Custom Field: The custom field that is expected might not be defined in the system or is not available in the context where it is being used.
  Incorrect Prefix: The prefix required for the custom field is not being used, which can lead to the system not recognizing the field as a custom one.
  
  Solution:
  
  Check Parameter Definition: Review the definition of the parameter in the program or function module. Ensure that it is defined as a custom field and that it matches the expected data type.
  Define Custom Field: If the custom field is missing, you may need to create it in the relevant data dictionary (SE11) or through the appropriate enhancement framework.
  Use Correct Prefix: Ensure that the prefix for the custom field is correctly specified. Custom fields often have specific naming conventions or prefixes (like Z or Y) that must be adhered to.
  Debugging: If you are unsure where the error is occurring, use the debugging tools in SAP to trace the execution and identify where the incorrect parameter is being passed.
  
  Related Information:
  
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message. Sometimes, there are specific fixes or recommendations provided by SAP.
  Documentation: Review the documentation for the specific function module or program you are working with to understand the expected parameters and their types.
  Community Forums: Consider searching or posting on SAP community forums or platforms like SAP Community, Stack Overflow, or other technical forums for additional insights from other developers who may have encountered the same issue.
  
  By following these steps, you should be able to identify the root cause of the CPF121 error and implement a solution to resolve it.