How To Fix CN520 - External Network Activity cannot be selected for network scheduling

CN520 - Overview

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 520

• Message text: External Network Activity cannot be selected for network scheduling

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

Unfortunately, there isn't any extra information in this error notice.

What else can you do?

First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).

Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.

You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.

Smart SAP Assistant

• What is the cause and solution for SAP error message CN520 - External Network Activity cannot be selected for network scheduling ?

  The SAP error message CN520 ("External Network Activity cannot be selected for network scheduling") typically occurs in the context of project management and network scheduling within SAP's Project System (PS) module. This error indicates that the system is unable to schedule an external network activity, which is often due to the nature of the activity or its configuration.
  
  Cause:
  
  
  External Activity Type: The activity in question is marked as an external activity, which means it is not intended to be scheduled within the internal network of the project. External activities are usually linked to external resources or vendors and are not part of the internal scheduling process.
  
  
  Network Configuration: The network might be configured in such a way that it does not allow for external activities to be included in the scheduling process.
  
  
  Dependencies: There may be dependencies or constraints that prevent the scheduling of the external activity within the current network.
  
  
  Status of the