How To Fix CL059 - You cannot extend classes using reference characteristics

CL059 - Overview

• Message type: E = Error

• Message class: CL - Classification

• Message number: 059

• Message text: You cannot extend classes using reference characteristics

What causes this issue?

You want to add a <DS:GLOS.reference_characteristic>reference
characteristic</> to a class. The reference characteristic is linked to
a field in the master record of the object you want to classify. For
classes of this class type, the field value is stored both in the
object master record and in classification tables.
Objects have already been allocated to the class. Therefore you can no
longer add characteristics that have a link to a field in master data
tables as this would cause inconsistencies.

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.

Smart SAP Assistant

• What is the cause and solution for SAP error message CL059 - You cannot extend classes using reference characteristics ?

  The SAP error message CL059, which states "You cannot extend classes using reference characteristics," typically occurs in the context of ABAP Object-Oriented programming when you are trying to extend a class that has reference characteristics (like reference types) in a way that is not allowed by the ABAP language rules.
  
  Cause:
  The error arises when you attempt to create a subclass of a class that has reference characteristics (like reference variables or reference types) and you try to extend it in a manner that is not permissible. In ABAP, reference types cannot be extended in the same way as value types. This restriction is in place to maintain the integrity of the reference types and their behavior.
  
  Solution:
  To resolve this error, consider the following approaches:
  
  
  Check Class Definition: Review the class you are trying to extend. Ensure that you are not trying to extend reference types in a way that is not allowed. If