How To Fix E0778 - First extension segment of reference segment cannot be changed

E0778 - Overview

• Message type: E = Error

• Message class: E0 - SAP EDI messages

• Message number: 778

• Message text: First extension segment of reference segment cannot be changed

What causes this issue?

The first extension segment of a reference segment cannot be changed in
the case of successors of extensions for compatibility reasons.

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?

Error message extract from SAP system. Copyright SAP SE.

E0778 - Details

• The SAP error message E0778, which states "First extension segment of reference segment cannot be changed," typically occurs in the context of SAP's data management and configuration processes, particularly when dealing with reference segments in the context of extensions or modifications to data structures.
  
  Cause:
  This error usually arises when there is an attempt to modify the first extension segment of a reference segment that is not allowed. In SAP, reference segments are often used to define a standard structure that can be extended or modified. However, certain restrictions are in place to maintain data integrity and consistency. The first extension segment is often considered a critical part of the reference structure, and changes to it may violate these integrity rules.
  
  Solution:
  To resolve this error, consider the following steps:
  
  
  Review the Data Model: Check the data model and the structure of the reference segment you are trying to modify. Ensure that you are not