How To Fix CNV_DMC_SIN266 - Class &1 / &2 already exists

SAP Error Message - Details

• Message type: E = Error

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

• Message number: 266

• Message text: Class &1 / &2 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.

Unfortunately, there isn't any extra information in this error notice.

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Smart SAP Assistant

• What is the cause and solution for SAP error message CNV_DMC_SIN266 - Class &1 / &2 already exists ?

  The SAP error message CNV_DMC_SIN266 typically indicates that there is an attempt to create or insert a record in a database table where a record with the same key already exists. This error is often encountered during data migration or conversion processes, particularly when using the SAP Data Migration Cockpit or similar tools.
  Cause:
  
  Duplicate Entries: The most common cause is that the data being imported or migrated contains duplicate entries for a unique key or primary key constraint in the target database table.
  Data Preparation Issues: The source data may not have been properly cleaned or deduplicated before the migration process.
  Incorrect Mapping: There may be an issue with how the source data is mapped to the target structure, leading to conflicts.
  Previous Migration Attempts: If a migration process was previously run and not completed successfully, it may have left behind records that are causing conflicts.
  
  Solution:
  
  Identify Duplicates: Review the source data to identify any duplicate entries that may be causing the conflict. You can use tools like Excel or SQL queries to find duplicates based on the unique key.
  Data Cleansing: Clean the source data to remove duplicates or consolidate records as necessary before attempting the migration again.
  Check Mapping: Ensure that the mapping of fields from the source to the target is correct and that there are no conflicts in the data structure.
  Delete Existing Records: If appropriate, you may need to delete the existing records in the target table that are causing the conflict before re-running the migration.
  Use Transaction Codes: If applicable, use transaction codes like SE11 to check the table structure and constraints, or SE16 to view existing records in the target table.
  Log Analysis: Check the migration logs for more detailed error messages that can provide additional context on the issue.
  
  Related Information:
  
  SAP Notes: Check SAP Notes for any known issues or patches related to the CNV_DMC_SIN266 error.
  Documentation: Review the documentation for the specific data migration tool you are using, as it may provide additional troubleshooting steps or best practices.
  Community Forums: Engage with SAP community forums or support channels for insights from other users who may have encountered similar issues.
  
  By following these steps, you should be able to resolve the CNV_DMC_SIN266 error and successfully complete your data migration process.