How To Fix CN406 - You cannot delete: Milestone is assigned to billing schedule

CN406 - Overview

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 406

• Message text: You cannot delete: Milestone is assigned to billing schedule

What causes this issue?

The milestone is assigned to a billing schedule. When this is the case,
you cannot delete the milestone.

System Response

INCLUDE 'NA_ALLG_NOFUNKTION' OBJECT DOKU ID TX

How to fix this error?

You can delete the milestone only once you have deleted the milestone
in the billing schedule.

Error message extract from SAP system. Copyright SAP SE.

CN406 - Details

• The SAP error message CN406 indicates that you are trying to delete a milestone that is currently assigned to a billing schedule. This is a common issue in project management and billing processes within SAP, particularly in the context of project systems (PS) or sales and distribution (SD).
  
  Cause:
  The error occurs because the milestone you are attempting to delete is linked to a billing schedule. In SAP, milestones are often used to trigger billing events, and if a milestone is associated with a billing schedule, it cannot be deleted until that association is removed.
  
  Solution:
  To resolve this error, you can follow these steps:
  
  
  Check Billing Schedule: 
  
  Navigate to the billing schedule associated with the milestone. You can do this by going to the relevant project or sales order and checking the billing documents or schedules.
  
  
  
  Remove the Milestone from the Billing Schedule:
  
  If you have the necessary permissions, you can edit the billing schedule to