How To Fix CNV421 - Test run of conversion programs after end of selection is not allowed.

CNV421 - Overview

• Message type: E = Error

• Message class: CNV - Conversion: Messages for Conversion Services (CNCC)

• Message number: 421

• Message text: Test run of conversion programs after end of selection is not allowed.

What causes this issue?

You are trying to start a program in test mode, but according to the
status management information the data selection for this program has
already been completed in update mode.
If you run the program in test mode, the data in the conversion cluster
may be deleted, which in turn would lead to inconsistencies in some
conversion scenarios (delete-insert logic).

System Response

For this reason, it is no longer possible to start the program in test
mode.

Error message extract from SAP system. Copyright SAP SE.

CNV421 - Details

• The SAP error message CNV421 indicates that a test run of conversion programs is not allowed after the end of selection. This typically occurs in the context of data migration or conversion processes, particularly when using the SAP Conversion Tools or the SAP Data Migration Workbench.
  
  Cause:
  The error usually arises due to the following reasons:
  
  
  Test Run Restrictions: The system is configured to prevent test runs after the selection phase has been completed. This is a safeguard to ensure that data integrity is maintained during the conversion process.
  
  
  Incorrect Execution Mode: The program may have been executed in a mode that does not support test runs after certain operations have been completed.
  
  
  
  Configuration Issues: There may be specific settings or configurations in the conversion program that restrict the execution of test runs.
  
  
  
  Solution:
  To resolve this error, you can consider the following steps:
  
  
  Check Execution Mode: Ensure that you are running the conversion program in the correct