How To Fix CNV_DMC_UI_FW_EXCEPT052 - Unable to create instance of type &1; class is not unique

SAP Error Message - Details

• Message type: E = Error

• Message class: CNV_DMC_UI_FW_EXCEPT - Messages for exception classes

• Message number: 052

• Message text: Unable to create instance of type &1; class is not unique

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message CNV_DMC_UI_FW_EXCEPT052 - Unable to create instance of type &1; class is not unique ?

  The SAP error message CNV_DMC_UI_FW_EXCEPT052 indicates that there is an issue with creating an instance of a specific type because the class is not unique. This typically occurs in the context of the SAP Data Migration Cockpit (DMC) or during data migration processes where multiple classes or instances are conflicting.
  Cause:
  
  Multiple Implementations: The error often arises when there are multiple implementations of the same interface or class in the system. This can happen if there are custom developments or if multiple versions of a class exist in the system.
  Configuration Issues: Incorrect configuration settings in the DMC or related components can lead to ambiguity in class resolution.
  Transport Issues: If there have been recent transports that included changes to classes or interfaces, it might lead to inconsistencies in the system.
  
  Solution:
  
  
  Check Class Implementations: 
  
  Use transaction SE80 or SE11 to check for multiple implementations of the class or interface in question. Ensure that there is only one active implementation.
  If you find multiple implementations, you may need to remove or deactivate the unnecessary ones.
  
  
  
  Review Custom Code: 
  
  If there are custom developments, review the code to ensure that it does not inadvertently create multiple instances of the same class.
  Check for any recent changes that might have introduced this issue.
  
  
  
  Clear Cache: 
  
  Sometimes, clearing the cache can resolve issues related to class loading. You can do this by using transaction code /n/SM12 to delete any locks or using transaction /n/SICF to refresh the service.
  
  
  
  Check DMC Configuration: 
  
  Review the configuration settings in the Data Migration Cockpit to ensure that everything is set up correctly and that there are no conflicting settings.
  
  
  
  Transport Management: 
  
  If the issue arose after a transport, check the transport logs for any errors or warnings that might indicate problems with the transported objects.
  
  
  
  Consult SAP Notes: 
  
  Search for relevant SAP Notes that might address this specific error. SAP frequently updates their knowledge base with solutions for known issues.
  
  
  
  Debugging: 
  
  If you have access to the development environment, consider debugging the code to identify where the error is being triggered. This can provide insights into why the class is not unique.
  
  
  
  Related Information:
  
  SAP Documentation: Refer to the official SAP documentation for the Data Migration Cockpit for more details on configuration and usage.
  SAP Community: Engage with the SAP Community forums to see if other users have encountered similar issues and what solutions they found effective.
  SAP Support: If the issue persists and you cannot find a resolution, consider reaching out to SAP Support for assistance.
  
  By following these steps, you should be able to identify the cause of the error and implement a solution to resolve it.