How To Fix CNV_DMC_MC026 - Rule &1 does not have a valid namespace; name must start with Y or Z

SAP Error Message - Details

• Message type: E = Error

• Message class: CNV_DMC_MC - Migration Object Modeler

• Message number: 026

• Message text: Rule &1 does not have a valid namespace; name must start with Y or Z

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message CNV_DMC_MC026 - Rule &1 does not have a valid namespace; name must start with Y or Z ?

  The SAP error message CNV_DMC_MC026 indicates that a rule defined in the Data Migration Cockpit (DMC) does not have a valid namespace. In SAP, custom objects (like rules, programs, etc.) must be created in a namespace that starts with either 'Y' or 'Z'. This is a convention used to differentiate custom developments from standard SAP objects.
  Cause:
  The error occurs when:
  
  A rule is created or referenced that does not follow the naming convention for custom objects.
  The rule's name starts with a character other than 'Y' or 'Z'.
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Identify the Rule: Determine which rule is causing the error. The error message should provide the name of the rule (indicated by &1).
  
  
  Check the Namespace: Verify the namespace of the rule. If it does not start with 'Y' or 'Z', you will need to rename it.
  
  
  Rename the Rule:
  
  Go to the relevant transaction in SAP (e.g., SE80 or SE11) where the rule is defined.
  Rename the rule to start with 'Y' or 'Z'.
  Ensure that the new name is unique and does not conflict with existing objects.
  
  
  
  Test the Changes: After renaming the rule, re-run the process that triggered the error to ensure that it is resolved.
  
  
  Documentation: Update any documentation or references to the rule to reflect the new name.
  
  
  Related Information:
  
  Namespaces in SAP: Custom objects in SAP are typically created in namespaces starting with 'Y' or 'Z' to avoid conflicts with standard SAP objects. This is a best practice in SAP development.
  Data Migration Cockpit (DMC): The DMC is a tool used for data migration in SAP S/4HANA projects. It allows users to define rules for data transformation and mapping.
  Error Handling: Always check the SAP Notes and documentation for any specific guidelines related to the Data Migration Cockpit and error handling.
  
  If you continue to experience issues after following these steps, consider reaching out to your SAP support team or consulting the SAP Community for further assistance.