When trying to generate client code for a WCF service, the following error occurs:
Error: Value cannot be null. (Parameter 'args')

Steps to reproduce

1. Download and extract AvangateServiceReference.zip
2. Run dotnet-svcutil AvangateServiceReference.wsdl --targetFramework net4.5

For reference, the original wsdl can be found here: https://api.avangate.com/soap/6.0/?wsdl

Expected behavior
I expected a c# proxy client to be generated.

Additional context
"C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.6.1 Tools\svcutil.exe" AvangateServiceReference.wsdl generates the code, but the methods don't have any parameters and the return types are void.