calling external system soap web service with automation agent

Summary:

I need to call external web service through otm action that fire agent to call external soap web service

Content:

here is my agent header

here is my agent action

here is my external system

and here is my wsdl document

i call it in this screen with custom action

it gives that error in the log (null pointer exception)

Version (Otm 24 A):

thanks..