How To Fix MU128 - Changes to the UoMs are not allowed for material &1.

SAP Error Message - Details

• Message type: E = Error

• Message class: MU - Maintenance of structured materials

• Message number: 128

• Message text: Changes to the UoMs are not allowed for material &1.

What causes this issue?

You have tried to change unit of measure data (UoM) of material &V1&.
This material is used in the context of logistical materials as a
procurement material. Adding or changing the units of measure of
procurement material is only permitted if a UoM is not used for the
associated sales material.

System Response

To keep the material data consistent, the system prevents you from
saving your changes.

How to fix this error?

If you want to transfer the material data by means of Application Link
Enabling (ALE), undo your unit of measure changes and transfer the data
again.
If you do not want to use material &V1& as a procurement material,
please make sure that the fields <LS>Category of a Logistical Material
</> and <LS>Material Number of a Sales Material</> are empty before
continuing to process the data.

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 MU128 - Changes to the UoMs are not allowed for material &1. ?

  The SAP error message MU128, which states "Changes to the UoMs are not allowed for material &1," typically occurs when there is an attempt to modify the unit of measure (UoM) for a material that is not permitted due to certain restrictions or settings in the system.
  Cause:
  
  Material Status: The material may be in a status that does not allow changes to its unit of measure. For example, if the material is blocked or has been marked for deletion.
  Transaction Type: Certain transactions or processes may restrict changes to the UoM, especially if the material is already being used in transactions (e.g., sales orders, purchase orders).
  Configuration Settings: The configuration settings in the material master may restrict changes to the UoM after certain conditions are met (e.g., after the material has been used in a transaction).
  Data Consistency: The system may prevent changes to ensure data consistency, especially if the material is linked to other documents or processes.
  
  Solution:
  
  Check Material Status: Verify the status of the material in the material master. If it is blocked or marked for deletion, you may need to change its status before making modifications.
  Review Transactions: Ensure that there are no open transactions (like sales orders, purchase orders, or stock movements) that are using the material. If there are, you may need to close or delete those transactions first.
  Use the Correct Transaction: If you are trying to change the UoM through a transaction that does not allow it, consider using the appropriate transaction code (e.g., MM02 for changing material master data).
  Consult Configuration: If you have access to configuration settings, check if there are any restrictions set in the material master configuration that prevent changes to the UoM.
  Contact SAP Support: If you are unable to resolve the issue, consider reaching out to your SAP support team or consulting SAP documentation for further assistance.
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with relevant transaction codes such as MM01 (Create Material), MM02 (Change Material), and MM03 (Display Material).
  Material Master Data: Understand the structure of material master data and how UoMs are defined and used within your organization.
  SAP Notes: Check for any SAP Notes related to this error message for additional insights or patches that may address the issue.
  User Authorizations: Ensure that you have the necessary authorizations to make changes to the material master data.
  
  By following these steps, you should be able to identify the cause of the MU128 error and take appropriate action to resolve it.