Thanks for the response. I understood what is happening with the externalTask returning null. I have defined the external tasks as asynchronous before and seems like we don’t need to do it anymore as they’re already a save point, according to one of your previous comment’s i found here - UnitTest for BPMN-workflow with an external task - #6 by Ingo_Richtsmeier.
I will check the integration tests and other scopes link above. I do have one last question here, if we don’t need to specify an external task as Asynchronous before then why do we have the checkbox on this item in camunda modeler ? Will this be fixed in future release ? Thanks