SOAP Integration

Hello All

Trying to test SOAP service(.svc) using "webservicequery" from Appian. I see the following error.

"Expression evaluation error at function 'webservicequery': The WSDL cannot be processed. It contains invalid or unsupported elements"
Service "serviceurl" was not found in the WSDL.

Below are my approaches i did for debugging

1)Using SOAP UI , I was able to connect and test the service.

2)I tried using smart service "call webservice" ,authentication went through, but some of the input parameters are optional.By default appian added all those parameters and passing some values, i am unable to delete. So its failing because of empty values sent for all optional parameters.By any chance whether can we remove the optional parameters that populated by default in the appian(Data tab in the process model). So reached to the service development  team to see whether they can do something on those parameters. below is the message 

Error Message : s:Fault xmlns:s="">schemas.xmlsoap.org/.../"><faultcode xmlns:a="">schemas.microsoft.com/.../faultcode><faultstring xml:lang="en-US">The formatter threw an exception while trying to deserialize the message: There was an error while trying to deserialize parameter urn:urn-1:Apis.v5.ProntoService.svc:userDetailsRequestModel. The InnerException message was 'Invalid enum value '' cannot be deserialized into type 'Alpha.Pronto.ServiceContracts.Option+UserProcessAuthorityTypes'. Ensure that the necessary enum values are present and are marked with EnumMemberAttribute attribute if the type has DataContractAttribute attribute.'. Please see InnerException for more details.</faultstring></s:Fault>

3) Meanwhile tried using webservicequery, i am getting error message "Expression evaluation error at function 'webservicequery': The WSDL cannot be processed. It contains invalid or unsupported elements"
Service "serviceurl" was not found in the WSDL

please let me know if i missing something to connect to service developed using dotnet.(.svc) . From Appian couldnt locate service for some reason.
Is this because of .svc format?.

Please let me know is there any work around or did i miss something here.

Thanks for your help.