How To Fix CN021 - You cannot create a subnetwork for activity element "&"

CN021 - Overview

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 021

• Message text: You cannot create a subnetwork for activity element "&"

What causes this issue?

'&V1&' is an activity element. You cannot create subnetworks for
activity elements.

System Response

INCLUDE 'NA_ALLG_NOFUNKTION' OBJECT DOKU ID TX

How to fix this error?

Check whether you have entered the correct activity number. Change
your entry, if necessary.

Error message extract from SAP system. Copyright SAP SE.

CN021 - Details

• The SAP error message CN021 indicates that you cannot create a subnetwork for a specific activity element in a project. This error typically arises in the context of project management within SAP, particularly when dealing with networks and activities in the Project System (PS) module.
  
  Cause:
  The error CN021 can occur due to several reasons:
  
  Invalid Activity Element: The activity element you are trying to create a subnetwork for may not be valid or may not support subnetworks.
  Hierarchy Restrictions: The structure of the project or network may not allow for the creation of subnetworks at that particular level.
  Activity Status: The status of the activity element may prevent modifications, such as creating subnetworks.
  
  Configuration Issues: There may be configuration settings in the project system that restrict the creation of subnetworks for certain types of activities.
  
  
  Solution:
  To resolve the CN021 error, you can take the following steps:
  
  
  Check Activity Element: Verify that the activity element you are trying