How To Fix SMT_CONFIG124 - Field &1 is not defined as a change structure key field

SAP Error Message - Details

• Message type: E = Error

• Message class: SMT_CONFIG - Configuration message class

• Message number: 124

• Message text: Field &1 is not defined as a change structure key field

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message SMT_CONFIG124 - Field &1 is not defined as a change structure key field ?

  The SAP error message SMT_CONFIG124 indicates that a specific field (denoted as &1 in the error message) is not defined as a key field in a change structure. This error typically arises in the context of SAP's System Landscape Transformation (SLT) or when configuring data replication scenarios.
  Cause:
  
  Field Not Defined as Key: The field you are trying to use in a change structure is not marked as a key field in the relevant table or structure. In SLT, key fields are essential for identifying unique records during data replication.
  Configuration Issues: There may be a misconfiguration in the SLT configuration settings or the data model that does not align with the source system's structure.
  Data Model Changes: If there have been recent changes to the data model (e.g., adding or removing fields), the change structure may not have been updated accordingly.
  
  Solution:
  
  
  Check Field Definition:
  
  Go to the Data Dictionary (transaction SE11) and check the definition of the table or structure in question.
  Ensure that the field you are trying to use is defined as a key field.
  
  
  
  Update Change Structure:
  
  If the field is not defined as a key field, you may need to modify the change structure to include it as a key field.
  This can typically be done in the SLT configuration settings or by using the relevant transaction for managing change structures.
  
  
  
  Reconfigure SLT:
  
  If necessary, reconfigure the SLT settings to ensure that the data model reflects the current structure of the source system.
  You may need to regenerate the configuration or reinitialize the data replication.
  
  
  
  Consult Documentation:
  
  Review SAP documentation or notes related to SLT and change structures for any specific guidelines or requirements regarding key fields.
  
  
  
  Testing:
  
  After making changes, test the configuration to ensure that the error is resolved and that data replication works as expected.
  
  
  
  Related Information:
  
  Transaction Codes: You may need to use transaction codes like SLT_CONFIG for SLT configuration or SE11 for checking table definitions.
  SAP Notes: Check for any relevant SAP Notes that might address this specific error or provide additional troubleshooting steps.
  SLT Documentation: Refer to the official SAP documentation for SLT for best practices on configuring change structures and key fields.
  
  If the issue persists after following these steps, consider reaching out to your SAP support team or consulting with an SAP expert for further assistance.