How To Fix CN818 - Relationships cannot be maintained

SAP Error Message - Details

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 818

• Message text: Relationships cannot be maintained

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.

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Smart SAP Assistant

• What is the cause and solution for SAP error message CN818 - Relationships cannot be maintained ?

  The SAP error message CN818 ("Relationships cannot be maintained") typically occurs in the context of project management or network planning within the SAP system, particularly when dealing with the assignment of relationships between activities in a project or network.
  Cause:
  The error CN818 can arise due to several reasons, including:
  
  Invalid Activity Status: The activity you are trying to maintain relationships for may be in a status that does not allow changes (e.g., completed or closed).
  Incorrect Project Structure: The project structure may not allow for the relationships you are trying to create or modify. For example, if the activities are not properly linked or if there are inconsistencies in the project hierarchy.
  Missing Authorizations: The user may not have the necessary authorizations to maintain relationships for the activities in question.
  Locked Activities: The activities may be locked for editing due to ongoing processes or other users working on them.
  System Configuration Issues: There may be configuration settings in the project management module that restrict the maintenance of relationships.
  
  Solution:
  To resolve the CN818 error, you can take the following steps:
  
  
  Check Activity Status: Ensure that the activities you are trying to maintain relationships for are in a status that allows changes. If they are completed or closed, you may need to reopen them or create new activities.
  
  
  Review Project Structure: Verify the project structure and ensure that the activities are correctly linked. Check for any inconsistencies or errors in the project hierarchy.
  
  
  Authorization Check: Confirm that you have the necessary authorizations to maintain relationships. If not, contact your SAP administrator to obtain the required permissions.
  
  
  Unlock Activities: If the activities are locked, check if another user is currently editing them. You may need to wait until they are finished or coordinate with them to unlock the activities.
  
  
  Consult Configuration Settings: If you suspect that configuration settings are causing the issue, consult with your SAP project management module administrator to review and adjust the settings as necessary.
  
  
  Use Transaction Codes: Utilize relevant transaction codes (like CN22 for network activities) to check the status and relationships of the activities.
  
  
  Related Information:
  
  SAP Notes: Check SAP Notes for any known issues or patches related to the CN818 error. SAP frequently updates its knowledge base with solutions for common errors.
  Documentation: Refer to SAP documentation for project management and network planning to understand the rules and constraints regarding activity relationships.
  Community Forums: Engage with SAP community forums or user groups where similar issues may have been discussed, and solutions shared.
  
  If the problem persists after trying the above solutions, it may be beneficial to escalate the issue to your SAP support team for further investigation.