How To Fix /SCWM/UI_CANCPICK030 - Locking conflict: Selected HUs are already locked by another process

SAP Error Message - Details

• Message type: E = Error

• Message class: /SCWM/UI_CANCPICK -

• Message number: 030

• Message text: Locking conflict: Selected HUs are already locked by another process

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.

Unfortunately, there isn't any extra information in this error notice.

What else can you do?

First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).

Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.

You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.

Smart SAP Assistant

• What is the cause and solution for SAP error message /SCWM/UI_CANCPICK030 - Locking conflict: Selected HUs are already locked by another process ?

  The SAP error message /SCWM/UI_CANCPICK030 Locking conflict: Selected HUs are already locked by another process typically occurs in the SAP Extended Warehouse Management (EWM) module when there is an attempt to process Handling Units (HUs) that are already locked by another transaction or process. This locking mechanism is in place to prevent data inconsistencies and ensure that multiple processes do not interfere with each other when accessing the same resources.
  Cause:
  
  Concurrent Processes: The most common cause of this error is that another user or process is currently working with the same Handling Units. This could be due to picking, packing, or any other warehouse operation that involves the same HUs.
  Long-running Transactions: If a transaction takes too long to complete, it may hold locks on HUs longer than expected, causing other processes to fail with this error.
  System Configuration: In some cases, system settings or configurations may lead to unexpected locking behavior.
  
  Solution:
  
  
  Identify the Locking Process:
  
  Use transaction code SM12 to check for locks on the specific Handling Units. This will show you which user or process is holding the lock.
  If you identify a user or process that is no longer active, you may need to unlock the HUs manually (if appropriate).
  
  
  
  Wait and Retry:
  
  If the locking process is legitimate and necessary, you may need to wait until it completes. After that, you can retry your operation.
  
  
  
  Optimize Processes:
  
  Review the processes that are locking the HUs to see if they can be optimized to reduce the time they hold locks. This may involve improving transaction performance or breaking down large transactions into smaller ones.
  
  
  
  User Training:
  
  Ensure that users are trained to avoid long-running transactions that can lead to locking conflicts. Encourage them to complete their tasks promptly.
  
  
  
  System Monitoring:
  
  Implement monitoring tools to keep track of long-running transactions and locking issues. This can help in identifying and resolving issues proactively.
  
  
  
  Consult SAP Notes:
  
  Check for any relevant SAP Notes that may address known issues or provide patches related to locking behavior in your version of SAP EWM.
  
  
  
  Related Information:
  
  
  Transaction Codes: 
  
  SM12 - To view and manage locks.
  SM21 - To check system logs for any related errors or warnings.
  ST22 - To check for dumps that may provide additional context.
  
  
  
  Documentation: Review SAP documentation related to EWM and handling unit management for best practices and guidelines.
  
  
  Support: If the issue persists and cannot be resolved through the above steps, consider reaching out to SAP support for further assistance.
  
  
  By following these steps, you should be able to address the locking conflict and continue with your warehouse operations effectively.