How To Fix CL189 - Generated classes with prefix & cannot be changed.

SAP Error Message - Details

• Message type: E = Error

• Message class: CL - Classification

• Message number: 189

• Message text: Generated classes with prefix & cannot be changed.

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

Unfortunately, there isn't any extra information in this error notice.

What else can you do?

First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).

Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.

You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.

Smart SAP Assistant

• What is the cause and solution for SAP error message CL189 - Generated classes with prefix & cannot be changed. ?

  The SAP error message CL189, which states "Generated classes with prefix & cannot be changed," typically occurs when you attempt to modify a class that has been generated by the SAP system, particularly in the context of ABAP (Advanced Business Application Programming). This error is related to the way SAP handles generated classes, especially those that are created from certain tools or frameworks, such as the Business Object Processing Framework (BOPF) or other code generation tools.
  Cause:
  
  Generated Classes: The class you are trying to modify is a generated class, which means it was created automatically by the system based on certain definitions or configurations. These classes are usually prefixed with a specific identifier (e.g., Z or Y for custom classes).
  System Protection: SAP protects generated classes from being changed directly to ensure the integrity of the generated code. If changes were allowed, it could lead to inconsistencies and errors in the application.
  Development Guidelines: SAP has guidelines that discourage direct modifications to generated classes. Instead, developers are encouraged to use enhancement techniques or create subclasses.
  
  Solution:
  
  
  Avoid Direct Modifications: Instead of trying to modify the generated class directly, consider using one of the following approaches:
  
  Enhancements: Use enhancement points or customer exits to add your custom logic without changing the generated class.
  Subclasses: If you need to extend the functionality, create a subclass of the generated class and implement your changes there.
  Custom Implementations: If applicable, create your own custom classes that implement the required functionality instead of modifying the generated ones.
  
  
  
  Check for Enhancements: Look for any enhancement options provided by SAP for the specific functionality you are working with. This could include BAdIs (Business Add-Ins) or enhancement spots.
  
  
  Review Documentation: Consult the SAP documentation related to the specific framework or tool you are using to understand the best practices for extending or customizing the generated classes.
  
  
  Related Information:
  
  SAP Notes: Check SAP Notes for any specific guidance or updates related to the error message CL189. SAP frequently releases notes that provide solutions or workarounds for common issues.
  ABAP Development Guidelines: Familiarize yourself with the ABAP development guidelines provided by SAP, which outline best practices for working with generated classes and enhancements.
  Community Forums: Engage with the SAP community through forums like SAP Community or Stack Overflow, where you can find discussions and solutions related to similar issues.
  
  By following these guidelines, you can effectively work around the limitations imposed by the generated classes and implement your required functionality in a compliant manner.