How To Fix CN455 - Milestone belongs to a billing plan - cannot change assignments

CN455 - Overview

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 455

• Message text: Milestone belongs to a billing plan - cannot change assignments

What causes this issue?

You cannot change the assignment of the milestone to an activity,
because the milestone is assigned to a billing plan.

System Response

INCLUDE NA_ALLG_NOVERARBEITUNG OBJECT DOKU ID TX

How to fix this error?

If you want to assign the milestone to another activity, delete the
date from the billing plan first.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CN455 - Milestone belongs to a billing plan - cannot change assignments ?

  The SAP error message CN455 indicates that you are trying to change the assignment of a milestone that is part of a billing plan. This error typically occurs in the context of project management and billing processes within SAP, particularly when dealing with milestones in project systems (PS) or sales and distribution (SD).
  
  Cause:
  The error arises because the milestone you are attempting to modify is linked to a billing plan. In SAP, billing plans are used to define how and when billing occurs for a project or service. When a milestone is associated with a billing plan, it is locked for changes to ensure the integrity of the billing process. This prevents any modifications that could disrupt the billing cycle or the financial reporting associated with the project.
  
  Solution:
  To resolve the CN455 error, you can consider the following steps:
  
  
  Check the Billing Plan: Review the billing plan associated with the milestone. Ensure that