How To Fix CN075 - External processing required as purchase order exists

CN075 - Overview

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 075

• Message text: External processing required as purchase order exists

What causes this issue?

You are attempting to change the control key of an externally processed
activity. When you change the control key, the activity can no longer
be processed externally. Since there is already a purchase order for
this activity, the control key of the activity must allow
external processing.

System Response

INCLUDE 'NA_ALLG_NOVERARBEITUNG' OBJECT DOKU ID TX

How to fix this error?

Select a control key which allows external processing.

Error message extract from SAP system. Copyright SAP SE.

CN075 - Details

• The SAP error message CN075 ("External processing required as purchase order exists") typically occurs in the context of project management and procurement processes within SAP. This error indicates that there is a purchase order (PO) associated with a project or network activity, and the system is preventing certain actions because of this association.
  
  Cause:
  
  Existing Purchase Order: The primary cause of this error is that there is an existing purchase order linked to the project or network activity you are trying to process. The system requires that any changes or actions that could affect the purchase order must be handled externally or through the appropriate procurement processes.
  Project Structure: The project structure may have dependencies that are tied to the purchase order, which restricts certain operations until the purchase order is resolved or processed.
  Configuration Settings: There may be specific configuration settings in the SAP system that enforce this behavior, particularly in project systems