How To Fix CNV_DMC_SIN258 - Unit of Measure: &1 already exists

SAP Error Message - Details

• Message type: E = Error

• Message class: CNV_DMC_SIN - Messages for s-innovations migration

• Message number: 258

• Message text: Unit of Measure: &1 already exists

What causes this issue?

With object 'Material - extend existing record by new org levels' you
can only extend new unit of measures. You can't change already existing
entries.

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?

Delete these records from the template.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CNV_DMC_SIN258 - Unit of Measure: &1 already exists ?

  The SAP error message CNV_DMC_SIN258 indicates that there is a conflict with the unit of measure (UoM) in the context of data migration or conversion processes, particularly when using the SAP Data Migration Cockpit (DMC) or similar tools. The message states that the specified unit of measure (represented by &1) already exists in the system.
  Cause:
  
  Duplicate Entry: The most common cause of this error is that the unit of measure you are trying to create or import already exists in the system. This can happen if the data being migrated includes UoMs that are already defined in the target SAP system.
  Data Consistency Issues: There may be inconsistencies in the data being migrated, such as multiple records for the same UoM or incorrect mappings.
  Configuration Issues: The configuration settings in the migration tool may not be set up correctly, leading to attempts to create UoMs that are already present.
  
  Solution:
  
  Check Existing UoMs: Before running the migration, check the existing units of measure in the target system to see if the UoM you are trying to import already exists. You can do this by navigating to the relevant transaction (e.g., CUNI for unit of measure maintenance).
  Modify Migration Data: If the UoM already exists, you may need to modify your migration data to either:
  
  Exclude the existing UoM from the migration.
  Update the existing UoM instead of trying to create a new one.
  
  
  Data Mapping: Ensure that your data mapping is correct and that you are not inadvertently trying to create duplicates.
  Error Handling: Implement error handling in your migration process to catch and log such errors for review.
  Consult Documentation: Review the SAP documentation related to the Data Migration Cockpit or the specific migration tool you are using for any additional guidelines or best practices.
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with transaction codes like CUNI (for unit of measure maintenance) and SE11 (for data dictionary) to help you investigate UoM definitions.
  SAP Notes: Check SAP Notes for any known issues or patches related to the Data Migration Cockpit or the specific error message.
  Migration Tools: If you are using a specific migration tool (like SAP S/4HANA Migration Cockpit), refer to the tool's documentation for specific instructions on handling UoM-related errors.
  
  By following these steps, you should be able to resolve the CNV_DMC_SIN258 error and successfully complete your data migration process.