class Program

{
    static void Main(string[] args)
    {
        HttpConfiguration config = new HttpConfiguration();
        config.Routes.MapHttpRoute("default", "{controller}({id})/{*pathinfo}");
        config.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;

        HttpServer server = new HttpServer(config);
        HttpClient client = new HttpClient(server);

        HttpResponseMessage response = client.GetAsync("http://localhost/Test(42)").Result;
        Console.WriteLine(response.Content.ReadAsStringAsync().Result);
    }
}

public class TestController : ApiController
{
    public int Get(int id)
    {
        return id;
    }
}

System.NullReferenceException occurred
HResult=-2147467261
Message=Object reference not set to an instance of an object.
Source=System.Web.Http
StackTrace:

   at System.Web.Http.ValueProviders.Providers.RouteDataValueProvider.<GetRoutes>d__4.MoveNext()

InnerException:

System.Web.Http.dll!System.Web.Http.ValueProviders.Providers.RouteDataValueProvider.GetRoutes(System.Web.Http.Routing.IHttpRouteData routeData) Line 21 + 0x3f bytes    C#
System.Web.Http.dll!System.Web.Http.ValueProviders.Providers.NameValuePairsValueProvider.InitializeValues(System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<string,string>> nameValuePairs) Line 54 + 0x165 bytes  C#
System.Web.Http.dll!System.Web.Http.ValueProviders.Providers.NameValuePairsValueProvider..ctor.AnonymousMethod__4() Line 34 + 0x1a bytes    C#
mscorlib.dll!System.Lazy<System.Collections.Generic.Dictionary<string,object>>.CreateValue() + 0xb5 bytes   
mscorlib.dll!System.Lazy<System.Collections.Generic.Dictionary<string,object>>.LazyInitValue() + 0x99 bytes 
mscorlib.dll!System.Lazy<System.Collections.Generic.Dictionary<string,object>>.Value.get() + 0x4c bytes 
System.Web.Http.dll!System.Web.Http.ValueProviders.Providers.NameValuePairsValueProvider.GetValue(string key) Line 104 + 0xd bytes  C#
System.Web.Http.dll!System.Web.Http.ValueProviders.Providers.CompositeValueProvider.GetValue(string key) Line 38 + 0xc bytes    C#
System.Web.Http.dll!System.Web.Http.ModelBinding.Binders.TypeConverterModelBinder.BindModel(System.Web.Http.Controllers.HttpActionContext actionContext, System.Web.Http.ModelBinding.ModelBindingContext bindingContext) Line 19 + 0x26 bytes  C#
System.Web.Http.dll!System.Web.Http.Controllers.HttpActionContextExtensions.Bind(System.Web.Http.Controllers.HttpActionContext actionContext, System.Web.Http.ModelBinding.ModelBindingContext bindingContext, System.Collections.Generic.IEnumerable<System.Web.Http.ModelBinding.IModelBinder> binders) Line 163 + 0xf bytes  C#
System.Web.Http.dll!System.Web.Http.ModelBinding.Binders.CompositeModelBinder.TryBind(System.Web.Http.Controllers.HttpActionContext actionContext, System.Web.Http.ModelBinding.ModelBindingContext bindingContext) Line 68 + 0x27 bytes    C#
System.Web.Http.dll!System.Web.Http.ModelBinding.Binders.CompositeModelBinder.BindModel(System.Web.Http.Controllers.HttpActionContext actionContext, System.Web.Http.ModelBinding.ModelBindingContext bindingContext) Line 38 + 0xf bytes   C#
System.Web.Http.dll!System.Web.Http.ModelBinding.ModelBinderParameterBinding.ExecuteBindingAsync(System.Web.Http.Metadata.ModelMetadataProvider metadataProvider, System.Web.Http.Controllers.HttpActionContext actionContext, System.Threading.CancellationToken cancellationToken) Line 57 + 0x18 bytes   C#