How To Fix CNV_20100242 - Proposed conversion routine cannot be changed for SAP tables

SAP Error Message - Details

• Message type: E = Error

• Message class: CNV_20100 - Messageclass for chart of account conversion

• Message number: 242

• Message text: Proposed conversion routine cannot be changed for SAP tables

What causes this issue?

You have tried to change a proposed or already assigned conversion
routine for an SAP table field.

System Response

SAP table fields have fixed conversion routines assigned, and you cannot
change these assignments.

How to fix this error?

Confirm the routine for now so that you can continue with your project.
After the conversion, double-check the results for this table field to
make sure that it has been converted correctly. If you find any
inconsistencies or other issues, contact SAP.

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 CNV_20100242 - Proposed conversion routine cannot be changed for SAP tables ?

  The SAP error message CNV_20100242, which states "Proposed conversion routine cannot be changed for SAP tables," typically occurs during data migration or conversion processes, particularly when using the SAP S/4HANA Migration Cockpit or other data migration tools. This error indicates that the system is trying to modify a conversion routine for a standard SAP table, which is not allowed.
  Cause:
  
  Standard SAP Tables: The error arises because the conversion routine for standard SAP tables is predefined and cannot be altered. This is a safeguard to maintain data integrity and consistency within the SAP system.
  Data Migration Process: During data migration, if the system detects an attempt to change the conversion routine for a standard table, it triggers this error.
  Custom Code or Enhancements: If there are custom enhancements or modifications in the migration process that attempt to change the conversion routine, this can also lead to the error.
  
  Solution:
  
  Review Migration Settings: Check the migration settings and ensure that you are not trying to change the conversion routine for standard SAP tables. Use the predefined routines as provided by SAP.
  Use Standard Routines: Stick to the standard conversion routines provided by SAP for the specific data types and tables you are working with.
  Consult Documentation: Refer to the SAP documentation for the specific migration tool you are using to understand the correct procedures and limitations regarding conversion routines.
  Error Handling: If you encounter this error, you may need to adjust your data mapping or transformation logic to comply with the standard routines.
  SAP Notes: Check for any relevant SAP Notes that may address this issue or provide additional guidance on handling data migration for the specific tables involved.
  
  Related Information:
  
  SAP Migration Cockpit: Familiarize yourself with the SAP S/4HANA Migration Cockpit, which provides tools and guidelines for data migration.
  Data Migration Best Practices: Review best practices for data migration in SAP, including data cleansing, mapping, and validation processes.
  SAP Community: Engage with the SAP Community or forums where other users may have encountered similar issues and can provide insights or solutions.
  
  If the problem persists after following these steps, consider reaching out to SAP support for further assistance.