Issue
When trying to call a WorkflowGen web service (\wfgen\ws\ProcessesRuntime.asmx), I receive an HTTP 401 error code.
Solution
The \wfgen\ws folder must be secured by using HTTP Basic authentication (secured with SSL if possible). Windows Integrated authentication is not supported.
You can also secure the \wfgen\ws folder with a custom HTTP module, which has to support application-to-application authentication (e.g. a form based authentication is not compatible because the web service is called by an another application).