How To Fix BOS01128 - Subpackage number cannot be changed for outline level &1

SAP Error Message - Details

• Message type: E = Error

• Message class: BOS01 - Customer BOS Processing

• Message number: 128

• Message text: Subpackage number cannot be changed for outline level &1

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message BOS01128 - Subpackage number cannot be changed for outline level &1 ?

  The SAP error message BOS01128, which states "Subpackage number cannot be changed for outline level &1," typically occurs in the context of project management or when dealing with structured data in SAP, such as in the Project System (PS) or other modules that utilize hierarchical structures.
  Cause:
  This error usually arises when there is an attempt to change the subpackage number of a project or a structured element that is already defined in the system. The subpackage number is a unique identifier for a specific outline level in a project structure, and once it is set, it cannot be modified. This restriction is in place to maintain data integrity and consistency within the project structure.
  Solution:
  To resolve this error, consider the following steps:
  
  
  Check the Outline Level: Verify the outline level (indicated by &1 in the error message) that you are trying to modify. Ensure that you are not attempting to change the subpackage number for an outline level that is already defined.
  
  
  Review Project Structure: If you need to change the subpackage number, you may need to create a new outline level or subpackage instead of modifying the existing one. This may involve restructuring your project.
  
  
  Consult Documentation: Refer to SAP documentation or help resources for specific guidelines on managing outline levels and subpackages in your version of SAP.
  
  
  Seek Help from SAP Support: If you are unable to resolve the issue, consider reaching out to your SAP support team or consulting with SAP experts who can provide guidance based on your specific configuration and requirements.
  
  
  Transaction Codes: Use relevant transaction codes (like CJ20N for project management) to navigate to the project structure and review the details of the outline levels.
  
  
  Related Information:
  
  SAP Notes: Check for any SAP Notes related to this error message, as they may provide additional insights or patches that could resolve the issue.
  User Roles and Permissions: Ensure that you have the necessary permissions to make changes to the project structure, as restrictions may also lead to errors.
  Training and Documentation: Familiarize yourself with SAP Project System (PS) or the specific module you are working with to understand how outline levels and subpackages are managed.
  
  By following these steps, you should be able to address the BOS01128 error effectively.