How To Fix OO243 - The prefix "CM_" is reserved for message classes

SAP Error Message - Details

• Message type: E = Error

• Message class: OO - Class Builder/API

• Message number: 243

• Message text: The prefix "CM_" is reserved for message classes

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Smart SAP Assistant

• What is the cause and solution for SAP error message OO243 - The prefix "CM_" is reserved for message classes ?

  The SAP error message OO243 indicates that there is an issue with the naming convention of message classes in the SAP system. Specifically, the prefix "CM_" is reserved for standard message classes, and using it for custom message classes can lead to conflicts and errors.
  Cause:
  The error occurs when a developer attempts to create a message class with a prefix that is reserved by SAP. In this case, "CM_" is reserved for standard message classes, and any attempt to create a custom message class with this prefix will trigger the OO243 error.
  Solution:
  To resolve this error, you should follow these steps:
  
  
  Rename the Message Class: Change the prefix of your custom message class to something other than "CM". For example, you could use "Z" or "Y_" as these prefixes are typically used for custom developments in SAP.
  
  
  Check Existing Message Classes: Before creating a new message class, check the existing message classes in the system to ensure that you are not using a reserved prefix.
  
  
  Use Transaction SE91: You can use transaction SE91 to manage message classes. Here, you can create, modify, or delete message classes. Ensure that you follow the naming conventions and avoid reserved prefixes.
  
  
  Transport Requests: If the message class is part of a transport request, ensure that the transport is updated with the new name if you change it.
  
  
  Related Information:
  
  
  Message Class Naming Conventions: SAP has specific naming conventions for message classes. Custom message classes typically start with "Z" or "Y". It's important to adhere to these conventions to avoid conflicts.
  
  
  Documentation: Refer to the SAP documentation for more information on message classes and their usage. This can provide insights into best practices and guidelines for naming conventions.
  
  
  SAP Notes: Check for any relevant SAP Notes that might provide additional context or updates regarding message classes and naming conventions.
  
  
  By following these steps and guidelines, you should be able to resolve the OO243 error and successfully create your custom message class without conflicts.