How To Fix MCEX166 - Update mode changed from serialized V3 update -> Long text

SAP Error Message - Details

• Message type: E = Error

• Message class: MCEX - Extraction Interface LIS/BW

• Message number: 166

• Message text: Update mode changed from serialized V3 update -> Long text

What causes this issue?

You have changed the update mode to "Serialized V3 Update".
Note that this mode will no longer be available in future plug-in
releases.
Furthermore, you need to keep in mind that this mode can cause
performance problems. These problems can occur especially if you
create/change documents in the OLTP system in different languages.

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?

Check to see if you can use the update modes "Delta Direct" or "Delta
Queued" for application &V1&.
<ZH>Important</>:
Before transporting the customizing requests for changing the update
mode in other systems, you <ZH>must</> check to see that no more
entries in this system are in the queue MCEX&V1&. It is possible to
check the target system in the logistics queue overview (transaction
LBWQ).

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message MCEX166 - Update mode changed from serialized V3 update -> Long text ?

  The SAP error message MCEX166 indicates that the update mode for a particular process has changed from a serialized V3 update to a different mode. This typically occurs in the context of the SAP system's update processing, particularly when dealing with data updates in the background.
  Cause:
  
  
  Update Mode Change: The error suggests that the system has detected a change in the update mode. This can happen due to various reasons, such as:
  
  Configuration changes in the update settings.
  Issues with the update framework or the way updates are being processed.
  A specific transaction or program that is not compatible with the serialized V3 update mode.
  
  
  
  Data Consistency Issues: If there are inconsistencies in the data being processed, the system may switch to a different update mode to handle the situation.
  
  
  Performance Considerations: Sometimes, the system may automatically switch modes to optimize performance or to avoid deadlocks.
  
  
  Solution:
  
  
  Check Update Configuration: Review the update configuration settings in the SAP system. Ensure that the settings for V3 updates are correctly configured and that there are no conflicting settings.
  
  
  Review Custom Code: If there are custom programs or enhancements that interact with the update process, review them for compatibility with the V3 update mode. Ensure that they are not inadvertently causing the mode change.
  
  
  Analyze Update Logs: Check the update logs for any additional error messages or warnings that may provide more context about why the update mode changed. This can help identify the root cause.
  
  
  Consult SAP Notes: Look for relevant SAP Notes that may address this specific error message. SAP frequently releases notes that provide solutions or workarounds for known issues.
  
  
  System Performance: Monitor system performance and resource utilization. If the system is under heavy load, consider optimizing the workload or increasing system resources.
  
  
  Testing: If changes are made to the configuration or custom code, conduct thorough testing to ensure that the issue is resolved and that the system behaves as expected.
  
  
  Related Information:
  
  SAP Documentation: Refer to the official SAP documentation for detailed information on update processing and the different update modes (V1, V2, V3).
  SAP Community: Engage with the SAP Community forums to see if other users have encountered similar issues and what solutions they have found.
  Transaction Codes: Familiarize yourself with relevant transaction codes such as SM13 (Update Records) and SM21 (System Log) to monitor and analyze update processes.
  
  If the issue persists after following these steps, it may be necessary to involve SAP support for further assistance.