How To Fix CNV256 - For table &, field &, routine & source package is not unique

CNV256 - Overview

• Message type: E = Error

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

• Message number: 256

• Message text: For table &, field &, routine & source package is not unique

What causes this issue?

The combination
table name &V1&
field name &V2&
routine &V3&
occurs in more than one source package. This causes a conflict.

System Response

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

How to fix this error?

Set field the source package manually

Error message extract from SAP system. Copyright SAP SE.

CNV256 - Details

• The SAP error message CNV256 typically indicates that there is a problem with the data conversion process, specifically related to the uniqueness of a source package in a data migration or conversion scenario. This error often arises during the execution of a data migration project, particularly when using SAP's data migration tools or during the execution of a custom program.
  
  Cause:
  The error message "For table &, field &, routine & source package is not unique" suggests that there is a conflict or ambiguity in the data being processed. This can occur due to several reasons:
  
  
  Duplicate Entries: There may be duplicate entries in the source data for the specified table and field, which makes it impossible for the system to determine which entry to use.
  
  
  Incorrect Mapping: The mapping of fields from the source to the target may not be correctly defined, leading to multiple potential matches.
  
  
  Data Integrity Issues: There may be issues