How To Fix IRW_LT091 - Lock failure; MT ID is already locked in another session

SAP Error Message - Details

• Message type: E = Error

• Message class: IRW_LT - ILM LT

• Message number: 091

• Message text: Lock failure; MT ID is already locked in another session

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message IRW_LT091 - Lock failure; MT ID is already locked in another session ?

  The SAP error message IRW_LT091 indicates a lock failure because the Material Transfer (MT) ID is already locked in another session. This typically occurs in scenarios where multiple users or processes are trying to access or modify the same material transfer ID simultaneously, leading to a conflict.
  Cause:
  
  Concurrent Access: Another user or process is currently using the same MT ID, which prevents your session from obtaining a lock on it.
  Long-running Transactions: If a transaction is taking too long to complete, it may hold the lock longer than expected, causing other sessions to fail when trying to access the same MT ID.
  System Configuration: Certain configurations in the SAP system may lead to more frequent locking issues, especially in high-transaction environments.
  
  Solution:
  
  Wait and Retry: The simplest solution is to wait for a few moments and then try to access the MT ID again. If the other session completes its transaction, the lock will be released.
  Identify the Lock: Use transaction code SM12 to check for existing locks. You can see which user or session is holding the lock on the MT ID. If necessary, you can contact the user to see if they can release the lock.
  Transaction Monitoring: If you frequently encounter this issue, consider monitoring the transactions that are causing the locks. This can help identify long-running processes that may need optimization.
  System Configuration Review: Review the system configuration and locking mechanisms to ensure they are optimized for your business processes. This may involve working with your SAP Basis team.
  Error Handling in Custom Code: If you have custom code that interacts with MT IDs, ensure that it properly handles locking scenarios to avoid unnecessary lock contention.
  
  Related Information:
  
  Transaction Codes: 
  
  SM12: To view and manage locks.
  SM21: To check system logs for any related issues.
  ST22: To check for dumps that might indicate underlying issues.
  
  
  SAP Notes: Check SAP Notes for any known issues or patches related to locking mechanisms in your version of SAP.
  Performance Tuning: Consider performance tuning for transactions that frequently cause locks, which may involve optimizing database queries or adjusting transaction logic.
  
  If the problem persists after trying the above solutions, it may be beneficial to engage with your SAP support team or consult SAP documentation for further troubleshooting steps.