org.camunda.bpm.engine.ProcessEngineException: Unknown property used in expression: ${abcServiceDelegate}. Cause: Cannot resolve identifier 'abcServiceDelegate'

i am using delegate expression under service task, some times i get this exception and some times it works.
Not able to resolve this, can someone help me

Hello @gowtham_m,
Can you describe your setup in more detail? It seems to be related to your cluster setup.
Here you find documentation regarding the job executor:

Best, McAlm