How To Fix ACO401 - Substitutes for '&1' have already been changed by another user

SAP Error Message - Details

• Message type: E = Error

• Message class: ACO - Error Messages for Package ACO

• Message number: 401

• Message text: Substitutes for '&1' have already been changed by another user

What causes this issue?

You entered or deleted substitutes for '&V1&' and want to save the
changes. However, these substitutes have meanwhile been changed and then
saved by one or more other users.

System Response

The system does not allow you to save the changed substitutes for '&V1&'
and discards the changes you made because they are based on data that is
no longer up-to-date. Moreover, the updated substitutes for '&V1&' are
being loaded.

How to fix this error?

Check the updated substitutes for '&V1&' and change them if this is
still necessary.

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 ACO401 - Substitutes for '&1' have already been changed by another user ?

  The SAP error message ACO401 indicates that there is a conflict when trying to change substitutes for a specific object (denoted by '&1') because another user has already made changes to those substitutes. This typically occurs in scenarios where multiple users are trying to edit the same data simultaneously, leading to a lock situation.
  Cause:
  
  Concurrent Access: Another user has already modified the substitutes for the specified object, and the system has locked that data to prevent inconsistencies.
  Session Conflicts: If a user has multiple sessions open and is trying to change the same data in different sessions, it can lead to this error.
  Data Locking Mechanism: SAP uses a locking mechanism to ensure data integrity. When one user is editing data, it locks that data for other users until the first user saves or cancels their changes.
  
  Solution:
  
  Refresh the Data: If you encounter this error, try refreshing the screen or reloading the data. This may allow you to see the latest changes made by other users.
  Wait and Retry: If another user is currently editing the data, you may need to wait until they finish and save their changes before you can make your own modifications.
  Check for Active Sessions: Ensure that you do not have multiple sessions open that are trying to edit the same data. Close any unnecessary sessions.
  Communicate with Other Users: If possible, communicate with the other user(s) to coordinate changes and avoid conflicts.
  Use Transaction Codes: If you are using a specific transaction code to make changes, ensure that you are following the correct process and that no other users are editing the same data at the same time.
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with the transaction codes related to the object you are trying to edit. This can help you understand the context of the changes being made.
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message. Sometimes, specific versions of SAP may have bugs that are documented in SAP Notes.
  User Lock Management: Administrators can check the lock entries in the system using transaction code SM12 to see if there are any locks on the object you are trying to edit. They can also release locks if necessary, but this should be done with caution to avoid data inconsistencies.
  
  By following these steps, you should be able to resolve the ACO401 error and continue with your work in SAP.