Remove all try and catch statements and let the error come as "SoapException was unhandled by code" error. In this case debugging will throw a message. See this message and click on ViewDetail under Action.
Under the View Detai, expand exception. See InnerXML under Detail: you will get the exact error. For example, I am getting this error from "
See the attached Image for more detail.
I hope this will help you to see detail error of