How To Fix WRF_APC321 - Target purchasing list &1 is already locked by user &2

WRF_APC321 - Overview

• Message type: E = Error

• Message class: WRF_APC - Messages for Operational Assortment Planning and Control

• Message number: 321

• Message text: Target purchasing list &1 is already locked by user &2

What causes this issue?

Purchasing list &V1& is currently being processed by user &V2& and
therefore cannot be changed.
Purchasing list items cannot be inserted into this purchasing list.
Items cannot be transferred or copied to this purchasing list.
Data transfer from the Layout Workbench to this purchasing list is not
possible.

System Response

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

How to fix this error?

Try again later when this purchasing list is no longer in use, or ask
the user who is currently processing it to exit so that you can perform
the desired action.
If you transfer data from the Layout Workbench to the corresponding
purchasing list, there are certain circumstances where it can appear
that you have locked yourself out. This can happen, for example, if you
release a Layout Module Version (which implicitly triggers a transfer of
data) and then choose the <LS>OAPC Transfer</> button immediately
afterwards (which explicitly triggers a transfer of data). The implicit
transfer might not yet be completed at the moment you are requesting the
explicit transfer. If this happens, just ignore the message and continue
processing.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message WRF_APC321 - Target purchasing list &1 is already locked by user &2 ?

  Certainly! Here's a detailed explanation for the SAP error message:
  
  SAP Error Message:
  WRF_APC321 Target purchasing list &1 is already locked by user &2
  
  Meaning / 
  Cause:
  This error occurs when you try to access or modify a Target Purchasing List (TPL) in SAP that is currently locked by another user. The system uses locks to prevent simultaneous changes to the same data object, ensuring data consistency and avoiding conflicts.
  
  &1 = Target Purchasing List number
  &2 = User ID who currently holds the lock
  
  The lock is typically set when a user opens the TPL for editing or processing, and it remains until the user finishes the transaction or the lock is released.
  
  Cause Details:
  
  Another user is currently working on the same Target Purchasing List.
  The lock has not been released due to the user still being active in the transaction or due to an abnormal termination (e.g., session crash).
  The system prevents you from making changes to avoid