How To Fix DMU020 - Alternative segment & already exists

SAP Error Message - Details

• Message type: E = Error

• Message class: DMU - Digital Mock Up (DMU)

• Message number: 020

• Message text: Alternative segment & already exists

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

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Smart SAP Assistant

• What is the cause and solution for SAP error message DMU020 - Alternative segment & already exists ?

  The SAP error message DMU020, which states "Alternative segment & already exists," typically occurs in the context of the SAP Data Migration Workbench or during the process of managing alternative segments in a data migration or master data management scenario. This error indicates that there is an attempt to create or define an alternative segment that already exists in the system.
  Cause:
  
  Duplicate Entry: The most common cause of this error is that the alternative segment you are trying to create or define already exists in the system. This could happen if the segment was previously created and not properly deleted or if there is a naming conflict.
  Data Migration Issues: During data migration, if the same alternative segment is being imported multiple times, it can lead to this error.
  Configuration Errors: Incorrect configuration settings or parameters in the data migration process can also lead to this error.
  
  Solution:
  
  Check Existing Segments: Before creating a new alternative segment, check the existing segments in the system to ensure that the one you are trying to create does not already exist. You can do this by navigating to the relevant transaction or table where alternative segments are stored.
  Delete or Modify Existing Segment: If you find that the segment already exists and you need to create a new one, consider deleting the existing segment if it is no longer needed or modifying it to meet your requirements.
  Use Unique Identifiers: When creating new alternative segments, ensure that you are using unique identifiers or names to avoid conflicts with existing segments.
  Review Data Migration Files: If this error occurs during a data migration process, review the data files being imported to ensure that there are no duplicate entries for alternative segments.
  Consult Documentation: Refer to SAP documentation or help resources for specific guidelines on managing alternative segments in your version of SAP.
  
  Related Information:
  
  Transaction Codes: Depending on your SAP version, you may use specific transaction codes to manage alternative segments, such as SE11 (Data Dictionary) or SE80 (Object Navigator).
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message. SAP Notes can provide additional context or solutions for specific scenarios.
  Support: If the issue persists after trying the above solutions, consider reaching out to SAP support for further assistance, providing them with detailed information about the error and the steps you have taken.
  
  By following these steps, you should be able to resolve the DMU020 error and successfully manage alternative segments in your SAP environment.