How To Fix APPLG406 - MUX: Key for synchronization job already exists

SAP Error Message - Details

• Message type: E = Error

• Message class: APPLG - Application Graphics Messages (Graphic Proxy Framework)

• Message number: 406

• Message text: MUX: Key for synchronization job already exists

What causes this issue?

An attempt was made to create a synchronization job that already
exists.
There exists at least one key that consists of the event code and the
master proxy (maybe with other slave graphics proxies as well).

How to fix this error?

Check the settings of the synchronization jobs in the controlling
application/master.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message APPLG406 - MUX: Key for synchronization job already exists ?

  The SAP error message APPLG406 with the description "MUX: Key for synchronization job already exists" typically occurs in the context of the SAP Landscape Management (LaMa) or when dealing with multiple instances of a system that are trying to synchronize or perform operations concurrently.
  Cause:
  The error indicates that there is an attempt to create a synchronization job with a key that already exists in the system. This can happen due to:
  
  Concurrent execution of synchronization jobs that are trying to use the same key.
  A previous synchronization job did not complete successfully, leaving the key in a locked state.
  A misconfiguration in the job scheduling or synchronization settings.
  
  Solution:
  To resolve this issue, you can take the following steps:
  
  
  Check Existing Jobs: 
  
  Use transaction codes like SM37 to check for any existing jobs that might be using the same key. Look for jobs that are in a running or waiting state.
  
  
  
  Cancel or Delete Conflicting Jobs:
  
  If you find any jobs that are still running or are stuck, you may need to cancel or delete them to free up the key. Ensure that you have the necessary permissions to do this.
  
  
  
  Review Job Configuration:
  
  Check the configuration of your synchronization jobs to ensure that they are set up correctly and that they are not trying to use the same key.
  
  
  
  Wait for Completion:
  
  If the job is still running, you may need to wait for it to complete before starting a new synchronization job.
  
  
  
  System Restart:
  
  In some cases, a system restart may help clear any locks or issues related to the synchronization jobs.
  
  
  
  Consult Documentation:
  
  Review SAP documentation or notes related to the specific version of SAP you are using for any known issues or additional troubleshooting steps.
  
  
  
  Contact SAP Support:
  
  If the issue persists after trying the above steps, consider reaching out to SAP support for further assistance. Provide them with the error message and any relevant logs or details about the jobs that are causing the issue.
  
  
  
  Related Information:
  
  SAP Notes: Check for any SAP Notes related to this error message for specific patches or updates that may address the issue.
  System Logs: Review system logs (transaction SLG1) for any additional error messages or warnings that may provide more context about the issue.
  Job Scheduling: Familiarize yourself with job scheduling best practices in SAP to avoid conflicts in the future.
  
  By following these steps, you should be able to resolve the APPLG406 error and successfully manage your synchronization jobs in SAP.