How To Fix CNV20305351 - Cycle merge is not supported.

SAP Error Message - Details

• Message type: E = Error

• Message class: CNV20305 - Messages for conversion packages in CO

• Message number: 351

• Message text: Cycle merge is not supported.

What causes this issue?

A merge of cycles is not supported as part of a controlling area merge.
Cycles which exist in the controlling areas which are to be merged must
be given a unique name in the mapping table.

System Response

When checking the mapping table, the system found that in the
controlling areas which are to be merged, there are cycles which would
be given the same name during conversion, which means that these cycles
would be merged.

How to fix this error?

Please check the mapping table for cycles and give all cycles unique
names.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CNV20305351 - Cycle merge is not supported. ?

  The SAP error message CNV20305351: Cycle merge is not supported typically occurs during data migration or transformation processes, particularly when using SAP's data migration tools or during system conversions. This error indicates that there is a cycle in the data relationships that the system cannot resolve, which prevents the merging of data records.
  Cause:
  
  Cyclic Relationships: The most common cause of this error is the presence of cyclic relationships in the data model. For example, if you have a hierarchy or a set of linked records that refer back to themselves, the system cannot determine the correct order to process these records.
  Data Integrity Issues: There may be issues with the integrity of the data, such as incorrect foreign key relationships or missing references that create cycles.
  Configuration Issues: Sometimes, the configuration of the migration tool or the settings in the SAP system can lead to this error if they do not properly handle cyclic dependencies.
  
  Solution:
  
  Identify Cycles: Review the data model and relationships to identify any cycles. This may involve examining the data in the relevant tables and understanding how they are linked.
  Data Cleanup: If cycles are found, you may need to clean up the data. This could involve:
  
  Removing or altering records that create cycles.
  Ensuring that foreign key relationships are correctly defined and do not create loops.
  
  
  Adjust Migration Logic: If you are using a custom migration logic or tool, you may need to adjust it to handle cyclic relationships appropriately. This could involve changing the order of processing or implementing logic to break cycles.
  Consult Documentation: Check the SAP documentation for the specific migration tool you are using. There may be specific guidelines or best practices for handling cyclic relationships.
  Testing: After making changes, conduct thorough testing to ensure that the data migration or transformation process works as expected without generating the error.
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that may address this specific error or provide additional guidance on handling cyclic merges.
  Community Forums: SAP Community and other forums can be valuable resources for finding similar issues faced by other users and the solutions they implemented.
  SAP Support: If the issue persists, consider reaching out to SAP Support for assistance, especially if this is part of a larger migration or upgrade project.
  
  By addressing the underlying causes of the cycle in your data relationships, you should be able to resolve the CNV20305351 error and successfully complete your data migration or transformation process.