How To Fix CN401 - Maintain fixed date only or reference to activity

SAP Error Message - Details

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 401

• Message text: Maintain fixed date only or reference to activity

What causes this issue?

When you enter a date for a milestone, you must note:
either enter a fixed date
or enter an offset of the milestone to the activity, for example, an
offset to the start or the key <LS>Start/fin.</>

System Response

INCLUDE 'NA_ALLG_NOVERARBEITUNG' OBJECT DOKU ID TX

How to fix this error?

Enter either
a fixed date
or an offset to start or finish
or the key <LS>Start/fin.</>

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CN401 - Maintain fixed date only or reference to activity ?

  The SAP error message CN401 typically occurs in the context of project management and is related to the scheduling of activities within a project. The message indicates that a fixed date must be maintained for the activity or that a reference to another activity should be established. Here’s a breakdown of the cause, solution, and related information for this error:
  Cause:
  
  Missing Fixed Date: The activity you are trying to schedule does not have a fixed date assigned to it. In project management, certain activities require a specific start or finish date to ensure proper scheduling and resource allocation.
  Reference Activity Not Defined: The activity may need to reference another activity that has a defined date. This is often necessary for dependencies between tasks.
  Project Settings: The project settings may require that all activities have either a fixed date or a reference to another activity, and if neither is provided, the error will be triggered.
  
  Solution:
  
  
  Maintain Fixed Date:
  
  Go to the activity in question and check the scheduling details.
  Assign a fixed start date or finish date to the activity.
  Ensure that the date is within the project timeline and does not conflict with other activities.
  
  
  
  Reference to Activity:
  
  If the activity should depend on another activity, identify the relevant predecessor or successor activity.
  Set the dependency by referencing the appropriate activity in the scheduling details.
  
  
  
  Check Project Settings:
  
  Review the project settings to understand the requirements for scheduling activities.
  If necessary, consult with your project manager or SAP administrator to ensure that the settings align with your project management practices.
  
  
  
  Related Information:
  
  Transaction Codes: You may need to use transaction codes such as CJ20N (Project Builder) or CJ02 (Change Project) to access and modify project activities.
  Documentation: Refer to SAP documentation or help files for detailed instructions on scheduling activities and managing project dependencies.
  User Roles: Ensure that you have the appropriate permissions to make changes to project activities, as some roles may have restricted access.
  
  Additional Tips:
  
  Always double-check the project timeline and dependencies before making changes to avoid scheduling conflicts.
  If you continue to encounter issues, consider reaching out to your SAP support team for further assistance.
  
  By following these steps, you should be able to resolve the CN401 error and successfully manage your project activities in SAP.