I'm having troubles using the smartstats webservice for /Services/Query.asmx/AvailableQueriesWithInputs

I can use /Services/Query.asmx/AvailableQueries with no problems, but when I try to do /Services/Query.asmx/AvailableQueriesWithInputs I get the following error ...

Grpc.Core.RpcException: Status(StatusCode=Unknown, Detail=&quot;Exception was thrown by handler.&quot;) at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Grpc.Core.Internal.AsyncCall`2.UnaryCall(TRequest msg) at Grpc.Core.DefaultCallInvoker.BlockingUnaryCall[TRequest,TResponse](Method`2 method, String host, CallOptions options, TRequest request) at Grpc.Core.Interceptors.InterceptingCallInvoker.<BlockingUnaryCall>b__3_0[TRequest,TResponse](TRequest req, ClientInterceptorContext`2 ctx) at Grpc.Core.ClientBase.ClientBaseConfiguration.ClientBaseConfigurationInterceptor.BlockingUnaryCall[TRequest,TResponse](TRequest request, ClientInterceptorContext`2 context, BlockingUnaryCallContinuation`2 continuation) at Grpc.Core.Interceptors.InterceptingCallInvoker.BlockingUnaryCall[TRequest,TResponse](Method`2 method, String host, CallOptions options, TRequest request) at SmarterStats.Grpc.Query.QueryClient.GetAvailableQueriesWithInputs(GetAvailableQueriesWithInputsRequest request, CallOptions options) at SmarterStats.Grpc.Query.QueryClient.GetAvailableQueriesWithInputs(GetAvailableQueriesWithInputsRequest request, Metadata headers, Nullable`1 deadline, CancellationToken cancellationToken) at SSWeb.Services.Query.AvailableQueriesWithInputs(String authUserName, String authPassword)

Any ideas?  I'm passing authUsername and authPassword just like with /Services/Query.asmx/AvailableQueries , but when I do /Services/Query.asmx/AvailableQueriesWithInputs I get the error?  

Any assistance would be useful.

Thanks,

David