How To Fix WRF_AT_GENERATE020 - System error locking purchase order &1

SAP Error Message - Details

• Message type: E = Error

• Message class: WRF_AT_GENERATE - Messages: Allocation Table Generation RTFASH/Ordering

• Message number: 020

• Message text: System error locking purchase order &1

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.

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Smart SAP Assistant

• What is the cause and solution for SAP error message WRF_AT_GENERATE020 - System error locking purchase order &1 ?

  The SAP error message:
  WRF_AT_GENERATE020: System error locking purchase order &1
  
  Cause:
  This error occurs when the system tries to lock a purchase order (PO) during a transaction or background process but fails. Locking is essential to prevent simultaneous changes to the same PO by multiple users or processes. The failure to lock the PO can be caused by:
  
  The PO is already locked by another user or process.
  A previous lock was not released properly due to a system crash or incomplete transaction.
  Deadlocks or lock wait timeouts in the SAP enqueue (locking) system.
  Issues with the enqueue server or lock table corruption.
  Network or system performance problems causing delays in lock handling.
  
  
  Solution:
  To resolve the error, consider the following steps:
  
  
  Check for existing locks:
  
  Use transaction SM12 to check if the PO is locked.
  If a lock exists and is no longer needed (e.g., from a crashed session), you can delete the lock manually from SM12 after confirming no active process is using it.
  
  
  
  Wait and retry:
  
  If the PO is locked by another active user/process, wait for the lock to be released and retry the operation.
  
  
  
  Analyze enqueue server:
  
  Check the status of the enqueue server (transaction SMEN).
  Restart the enqueue server if necessary (this requires system admin rights and should be done carefully).
  
  
  
  Check system logs:
  
  Use transaction SM21 to look for system errors or enqueue errors around the time the problem occurred.
  
  
  
  Review background jobs:
  
  If the error occurs in batch jobs, check if multiple jobs are trying to update the same PO simultaneously and adjust scheduling to avoid conflicts.
  
  
  
  Apply SAP Notes:
  
  Search for relevant SAP Notes on the SAP Support Portal using the error message or symptoms.
  Sometimes, patches or corrections are available for known enqueue or locking issues.
  
  
  
  
  Related Information:
  
  Transaction SM12: Display and manage lock entries.
  Transaction SMEN: Enqueue server monitor.
  Transaction SM21: System log for error analysis.
  Enqueue mechanism: SAP uses enqueue locks to ensure data consistency.
  SAP Notes: Check for notes related to enqueue errors or WRF_AT_GENERATE020.
  
  
  Summary:
  The error WRF_AT_GENERATE020 indicates a failure to lock a purchase order due to existing locks or enqueue system issues. The primary action is to check and clear locks in SM12, ensure no conflicting processes are running, and verify the health of the enqueue server. If the problem persists, consult SAP Notes or system logs for deeper analysis.