How To Fix OO_SOURCE_BASED103 - Modification Assistant can not be used by the source-based Class Builder.

OO_SOURCE_BASED103 - Overview

• Message type: E = Error

• Message class: OO_SOURCE_BASED - WB - Class Builder - Messages for the source-b. Class Editor

• Message number: 103

• Message text: Modification Assistant can not be used by the source-based Class Builder.

What causes this issue?

You have selected the source-based Class Builder in your user Settings
(Utilities->Settings...->Class Builder) as your default tool.
The Modification Assistant is enabled for the class or the interface
which you have opened. The source-based Class Builder does not support
the Modification Assistant.

System Response

The form-based Class Builder will be opened for the class or the
interface.

How to fix this error?

You can edit the class in the form-based Class Builder.

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.

OO_SOURCE_BASED103 - Details

• The SAP error message "OO_SOURCE_BASED103: Modification Assistant can not be used by the source-based Class Builder" typically occurs when you are trying to use the Modification Assistant in a context where it is not applicable, particularly when working with source-based class definitions in ABAP Object-Oriented programming.
  
  Cause:
  
  Source-Based Class Builder: The error indicates that you are attempting to use the Modification Assistant with a source-based class. The Modification Assistant is designed for use with the graphical class builder (Class Builder transaction SE24) and not with source-based classes (which are defined in the ABAP Editor).
  Incompatibility: The Modification Assistant is not compatible with certain types of class definitions, particularly those that are defined directly in the source code rather than through the Class Builder interface.
  
  
  Solution:
  
  Use Class Builder: If you need to modify a class, ensure that you are using the Class Builder (transaction SE24) instead of editing the class directly in the ABAP Editor