How To Fix COM_DML_CUST066 - Key field structure cannot be changed

COM_DML_CUST066 - Overview

• Message type: E = Error

• Message class: COM_DML_CUST - MDF Messages

• Message number: 066

• Message text: Key field structure cannot be changed

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 COM_DML_CUST066 - Key field structure cannot be changed ?

  The SAP error message COM_DML_CUST066 indicates that there is an attempt to change a key field in a structure that is not allowed. This typically occurs in the context of customizing or modifying data models, particularly in the area of configuration or data management.
  
  Cause:
  
  Key Field Modification: The error arises when there is an attempt to change a key field in a structure that is already defined in the system. Key fields are critical for identifying records uniquely, and changing them can lead to inconsistencies in data integrity.
  Data Model Constraints: The data model may have constraints that prevent changes to key fields once they are established. This is often enforced to maintain the integrity of the data and relationships within the database.
  Customizing Settings: The error may also occur if there are conflicting customizing settings or if the system is trying to apply changes that are not compatible with existing configurations.
  
  
  Solution:
  
  Review Changes: