CNV257 - For domain &, data element & and convfunc &, source package is not unique

SAP Error Message - Details

• Message type: E = Error

• Message class: CNV - Conversion: Messages for Conversion Services (CNCC)

• Message number: 257

• Message text: For domain &, data element & and convfunc &, source package is not unique

What causes this issue?

The combination
domain &V1&
data element &V2&
routine &V3&
occurs in more than one source package. This causes a conflict.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Set field source package for the domain / data element manually.

Error message extract from SAP system. Copyright SAP SE.

AnswerBot

• What is the cause and solution for SAP error message CNV257 - For domain &, data element & and convfunc &, source package is not unique ?

  The SAP error message CNV257 typically occurs during data migration or conversion processes, particularly when using the SAP S/4HANA Migration Cockpit or other data migration tools. This error indicates that there is an issue with the uniqueness of the source package for a specific domain, data element, and conversion function.
  Cause:
  The error message "For domain &, data element &, and convfunc &, source package is not unique" suggests that the system has encountered multiple source packages that match the criteria defined for the specified domain, data element, and conversion function. This can happen due to:
  
  Duplicate Entries: There are multiple entries in the source data that correspond to the same domain and data element, leading to ambiguity in the conversion process.
  Configuration Issues: The configuration of the migration or conversion process may not be set up correctly, causing the system to misinterpret the source data.
  Data Model Changes: Changes in the data model or structure may have resulted in multiple valid mappings for the same data element.
  
  Solution:
  To resolve the CNV257 error, you can take the following steps:
  
  
  Check Source Data: Review the source data for duplicates or inconsistencies. Ensure that there is a unique mapping for each entry in the source data to the target data model.
  
  
  Review Configuration: Examine the configuration settings for the migration or conversion process. Ensure that the mappings for the domain, data element, and conversion function are correctly defined and do not overlap.
  
  
  Adjust Mapping: If necessary, adjust the mapping rules to ensure that each source package is unique. This may involve creating additional transformation rules or modifying existing ones.
  
  
  Consult Documentation: Refer to SAP documentation or guides related to the specific migration or conversion tool you are using. There may be specific instructions or best practices for handling such errors.
  
  
  Use Transaction Codes: If applicable, use transaction codes like LTMC (for Migration Cockpit) or LTMOM (for Migration Object Modeler) to analyze and adjust the migration objects and mappings.
  
  
  Seek Support: If the issue persists, consider reaching out to SAP support or consulting with an SAP expert who can provide more tailored assistance based on your specific scenario.
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that may address this specific error or provide additional troubleshooting steps.
  Migration Cockpit: Familiarize yourself with the SAP S/4HANA Migration Cockpit and its functionalities, as it provides tools for data migration and may have specific features to handle such errors.
  Data Migration Best Practices: Review best practices for data migration in SAP environments to avoid common pitfalls that can lead to errors like CNV257.
  
  By following these steps, you should be able to identify the root cause of the CNV257 error and implement a solution to resolve it.