How To Fix USMD1551 - Model &1, entity type &2: Attribute &3 must not be a key field

SAP Error Message - Details

• Message type: E = Error

• Message class: USMD1 - Datenmodel

• Message number: 551

• Message text: Model &1, entity type &2: Attribute &3 must not be a key field

What causes this issue?

You have tried to make the &V3& attribute an additional key field of the
&V2& entity type. The system does not allow you to do this because the
&V2& entity type is configured as being relevant for hierarchies.

System Response

You are not allowed to save your changes.

How to fix this error?

Deselect the <LS>Key Field</> indicator for the &V3& attribute of the
&V2& entity type.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message USMD1551 - Model &1, entity type &2: Attribute &3 must not be a key field ?

  The SAP error message USMD1551 indicates that there is an issue with the data model configuration in the SAP Master Data Governance (MDG) system. Specifically, it states that an attribute (field) that you are trying to define as a key field in a model is not allowed to be a key field for the specified entity type.
  Cause:
  
  Incorrect Configuration: The attribute you are trying to set as a key field is not defined as a key field in the underlying data model for that entity type. Key fields are typically used to uniquely identify records in a database table, and not all attributes can serve this purpose.
  Data Model Restrictions: The data model may have specific restrictions on which attributes can be designated as key fields. This is often defined in the data model configuration and can vary based on the entity type.
  
  Solution:
  
  Review Data Model Configuration: Check the data model configuration for the entity type in question. Ensure that the attribute you are trying to set as a key field is indeed allowed to be a key field.
  Modify Key Field Settings: If the attribute is not allowed to be a key field, you will need to either:
  
  Choose a different attribute that is permitted to be a key field.
  Adjust the data model configuration if you have the necessary permissions and if it makes sense to do so.
  
  
  Consult Documentation: Refer to the SAP documentation for Master Data Governance to understand the rules and restrictions regarding key fields for the specific entity type you are working with.
  Seek Help from SAP Support: If you are unsure about the configuration or need further assistance, consider reaching out to SAP support or consulting with an SAP expert who can provide guidance based on your specific scenario.
  
  Related Information:
  
  Entity Types: Familiarize yourself with the different entity types in your MDG system and their respective attributes.
  Key Fields: Understand the role of key fields in data governance and how they impact data integrity and uniqueness.
  SAP Notes: Check for any relevant SAP Notes that may address this error or provide additional context or solutions.
  Training and Documentation: Consider training resources or documentation specific to SAP MDG to better understand data modeling and configuration.
  
  By following these steps, you should be able to resolve the error and correctly configure your data model in SAP MDG.