How To Fix CN251 - Invoicing plan only for externally procured components

CN251 - Overview

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 251

• Message text: Invoicing plan only for externally procured components

What causes this issue?

You can only maintain an invoicing plan for general cost activities,
external activities and externally procurred components.

Error message extract from SAP system. Copyright SAP SE.

CN251 - Details

• The SAP error message CN251 ("Invoicing plan only for externally procured components") typically occurs in the context of project systems (PS) or materials management (MM) when there is an attempt to create or process an invoicing plan for a component that is not externally procured. This error indicates that the invoicing plan functionality is only applicable to components that are procured from external vendors, not for internally produced or stock items.
  
  Cause:
  
  Component Type: The component you are trying to include in the invoicing plan is not marked as externally procured. This could be due to the material master settings or the way the component is defined in the project.
  Material Master Settings: The material may be set up as a stock item or internally produced, which does not allow for invoicing plans.
  Project Definition: The project or network activity may not be configured to allow invoicing plans for certain components.
  
  
  Solution:
  
  Check Material Master: Verify