How To Fix CNV_PE_CHECK026 - Error instantiating the transformation rule; see long text

CNV_PE_CHECK026 - Overview

• Message type: E = Error

• Message class: CNV_PE_CHECK - Check Framework messages for posting engine

• Message number: 026

• Message text: Error instantiating the transformation rule; see long text

What causes this issue?

The instantiation of the transformation rule failed with error message:
&V1&
Most likely the transformation rule was changed in a parallel session
(SAP GUI window), but you did <ZH>not </>close and reopen this session
after the change (in the first session) was saved.

System Response

Error

How to fix this error?

Leave this transaction and reopen it. Try the operation again.
If the error remains, contact SAP for support.

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.

CNV_PE_CHECK026 - Details

• The SAP error message CNV_PE_CHECK026 typically occurs during data migration or transformation processes, particularly when using the SAP S/4HANA Migration Cockpit or other data migration tools. This error indicates that there is an issue with instantiating a transformation rule, which is essential for mapping source data to the target structure.
  
  Cause:
  The error can be caused by several factors, including:
  
  Missing or Incorrect Transformation Rules: The transformation rules defined for the data migration might be missing, incomplete, or incorrectly configured.
  Data Type Mismatches: There may be a mismatch between the data types of the source and target fields, which prevents the transformation from being instantiated.
  
  Configuration Issues: There could be issues in the configuration of the migration project or the specific transformation rules.
  Dependencies Not Met: The transformation might depend on other rules or configurations that are not properly set up or are missing.
  Authorization Issues: The user executing the migration might not have the necessary authorizations