I never faced similar problem before,
I tried with SOAP 4.0.1 and also with SOAP 5.1.2. I tried it on my windows but also and on Windows Server 2008 I try to import WSDL: NT Authentication dialog is presented: Specify NT Authentication Credentials to populate Username,Password,Domain
I am able to open the WSDL definition in Firefox:
http://192.168.0.242/SO/Services/ScheduleService.svc?wsdl
after entering username and password
but when trying to import WSDL file or when trying to import wsdl file using location URL
Error loading WSDL
There was something wrong with the WSDL you are trying to import
Error loading
[http://192.168.0.242/SO/Services/ScheduleService.svc?wsdl=wsdl0]: org.apache.xmlbeans.XmlException:
org.apache.xmlbeans.XmlException: error: Reference to undefined entity: raquo
I got same error using latest Soap UI 5.3. No hacking with configuration helped (proxy none, authenticate preemptively etc). In the end I imported WSDL from disk. Calling of operations through NTLM then worked without any problems. It seems like a bug in SoapUI when importing WSDL through NTLM in some environments.
Update: tested that enabling anonymous auth and disabling windows auth in IIS resolves the issue with import in SoapUI. So it is definitely some kind of bug in SoapUI during import through NTLM.