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

APPLG406 - Overview

• 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.

APPLG406 - Details

• 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