How To Fix CMMD021 - Error in the hierarchy structure

SAP Error Message - Details

• Message type: E = Error

• Message class: CMMD -

• Message number: 021

• Message text: Error in the hierarchy structure

What causes this issue?

An error occurred when reading the hierarchy data from the database.
This error caused the program to terminate.
A possible reason for the error may be an incompletely maintained
hierarchy data record (a missing entry for the initial access node in
the article hierarchy).

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Check the relevant data records in the corresponding database tables.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CMMD021 - Error in the hierarchy structure ?

  The SAP error message CMMD021, which indicates "Error in the hierarchy structure," typically arises in the context of SAP's Master Data Management, particularly when dealing with hierarchical data structures such as those found in classification, materials management, or organizational structures.
  Cause:
  The error can be caused by several factors, including:
  
  Incorrect Hierarchy Structure: The hierarchy may not be properly defined, leading to inconsistencies in parent-child relationships.
  Missing Nodes: A node that is referenced in the hierarchy may not exist or may have been deleted.
  Circular References: There may be circular references in the hierarchy, where a node indirectly references itself.
  Data Integrity Issues: There may be issues with the underlying data, such as missing or incorrect attributes that are required for the hierarchy to function correctly.
  Authorization Issues: The user may not have the necessary permissions to view or modify the hierarchy.
  
  Solution:
  To resolve the CMMD021 error, you can take the following steps:
  
  
  Check Hierarchy Structure:
  
  Review the hierarchy structure in the relevant transaction (e.g., transaction codes like CSM1, CSM2 for classification).
  Ensure that all parent-child relationships are correctly defined and that there are no missing nodes.
  
  
  
  Validate Data:
  
  Use transaction codes like CSM1 or CSM2 to validate the hierarchy and check for any inconsistencies.
  Look for any nodes that may be missing or incorrectly defined.
  
  
  
  Check for Circular References:
  
  Ensure that there are no circular references in the hierarchy. This can often be done by manually reviewing the structure or using specific tools or reports designed to check for such issues.
  
  
  
  Review Authorizations:
  
  Ensure that the user has the necessary authorizations to access and modify the hierarchy. This can be checked in the user roles and profiles.
  
  
  
  Consult Documentation:
  
  Refer to SAP documentation or help resources for specific guidance on the hierarchy structure relevant to your module (e.g., SAP MM, SAP PM).
  
  
  
  Use SAP Notes:
  
  Check the SAP Support Portal for any relevant SAP Notes that may address this specific error or provide patches or updates.
  
  
  
  Contact SAP Support:
  
  If the issue persists after checking the above points, consider reaching out to SAP Support for further assistance.
  
  
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with relevant transaction codes for managing hierarchies, such as CSM1 (Create Class), CSM2 (Change Class), and CSM3 (Display Class).
  SAP Community: Engage with the SAP Community forums for insights and solutions shared by other users who may have encountered similar issues.
  Training and Documentation: Consider training sessions or documentation on SAP Master Data Management and hierarchy structures to better understand how to manage and troubleshoot these types of errors.
  
  By following these steps, you should be able to identify and resolve the CMMD021 error effectively.