How To Fix CN189 - A reference object cannot be entered for the method 'Update'

SAP Error Message - Details

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 189

• Message text: A reference object cannot be entered for the method 'Update'

What causes this issue?

A reference object has been entered for the object type 'Hierarchy' in
the "Update" command. A reference number and/or an object key has been
entered in the command table.

System Response

INCLUDE NA_ALLG_NOVERARBEITUNG OBJECT DOKU ID TX
&NOTE&
Always enter the complete hierarchy in the hierarchy table.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CN189 - A reference object cannot be entered for the method 'Update' ?

  The SAP error message CN189, which states "A reference object cannot be entered for the method 'Update'," typically occurs in the context of SAP Project System (PS) or related modules when there is an attempt to update a project or network activity with an invalid reference object.
  Cause:
  
  Invalid Reference Object: The error usually arises when the system expects a specific type of object (like a WBS element or network activity) but receives a reference object that is not valid for the operation being performed.
  Incorrect Method Usage: The method 'Update' may not be applicable for the type of object you are trying to reference. For example, if you are trying to update a project with a network activity reference that is not properly defined or does not exist.
  Configuration Issues: There may be configuration settings in the system that restrict the use of certain reference objects for updates.
  Authorization Issues: Sometimes, the user may not have the necessary authorizations to perform the update on the specified object.
  
  Solution:
  
  Check Reference Object: Ensure that the reference object you are trying to use is valid and exists in the system. Verify that it is the correct type for the update operation.
  Review Method Usage: Confirm that you are using the correct method for the operation you are trying to perform. If 'Update' is not appropriate, consider using a different method that aligns with the object type.
  Configuration Review: Check the configuration settings in the SAP system related to project management and ensure that they allow for the intended updates.
  Authorization Check: Verify that the user has the necessary permissions to perform updates on the specified reference object. If not, consult with your SAP security team to obtain the required authorizations.
  Consult Documentation: Refer to SAP documentation or help resources for specific guidance on the method and object types you are working with.
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with relevant transaction codes in SAP Project System, such as CJ20N (Project Builder) or CN22 (Change Network).
  SAP Notes: Check for any SAP Notes related to error CN189 for additional insights or patches that may address the issue.
  Debugging: If you have access, consider debugging the process to identify where the error is triggered and what specific data is causing the issue.
  Community Forums: Engage with SAP community forums or support channels for additional help from other users who may have encountered similar issues.
  
  By following these steps, you should be able to diagnose and resolve the CN189 error effectively.