How To Fix /PLMU/UI_GSS028 - Synchronization unit &1 is locked and cannot be synchronized

SAP Error Message - Details

• Message type: E = Error

• Message class: /PLMU/UI_GSS -

• Message number: 028

• Message text: Synchronization unit &1 is locked and cannot be synchronized

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 /PLMU/UI_GSS028 - Synchronization unit &1 is locked and cannot be synchronized ?

  The SAP error message /PLMU/UI_GSS028 Synchronization unit &1 is locked and cannot be synchronized typically indicates that a synchronization unit (which could be a business object, data set, or similar entity) is currently locked by another process or user, preventing the current operation from proceeding.
  Cause:
  
  Concurrent Access: Another user or process is currently accessing or modifying the synchronization unit, leading to a lock.
  Long-Running Transactions: A transaction that takes a long time to complete may hold a lock on the synchronization unit.
  System Configuration: Certain configurations or settings in the SAP system may lead to locking behavior.
  Deadlocks: In some cases, a deadlock situation may occur where two or more processes are waiting for each other to release locks.
  
  Solution:
  
  Wait and Retry: If the lock is temporary, waiting for a few moments and then retrying the operation may resolve the issue.
  Identify the Lock: Use transaction codes like SM12 (to view and manage locks) to identify which user or process is holding the lock on the synchronization unit.
  Terminate the Lock: If appropriate, you can terminate the session or process that is holding the lock. This should be done with caution and typically requires administrative privileges.
  Check for Long-Running Transactions: Investigate if there are any long-running transactions that can be optimized or terminated.
  Review System Configuration: Check the configuration settings related to locking mechanisms in your SAP system to ensure they are set appropriately.
  Consult Documentation: Refer to SAP Notes or documentation related to the specific module or functionality you are working with for any known issues or additional troubleshooting steps.
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with transaction codes like SM12 (lock entries), SM21 (system log), and ST22 (dump analysis) for troubleshooting.
  SAP Notes: Search the SAP Support Portal for relevant SAP Notes that may address this specific error or provide additional context.
  User Permissions: Ensure that users have the appropriate permissions to access and modify the synchronization unit.
  System Performance: Monitor system performance to identify any bottlenecks that may be causing locks to persist longer than necessary.
  
  If the issue persists after trying the above solutions, it may be beneficial to engage with your SAP Basis team or SAP support for further assistance.