Could not create an instance of type x Type is an interface or abstract class and cannot be instantiated.

We have been running JsonKnownTypes for quite a while running smoothly. But after updating to 0.4.1 we get random errors.

Newtonsoft.Json.JsonSerializationException: Could not create an instance of type InRange.Onprem.StreamProcessing.RawMessages.RawMessageBase. Type is an interface or abstract class and cannot be instantiated. Path 'accumulateddelay', line 1, position 20. The same message works when running a unit test seperately, but when running multiple unit tests in a batch then errors occur (strange I know).

Our base class:

[JsonConverter(typeof(JsonKnownTypesConverter<RawMessageBase>))]
    [JsonDiscriminator(Name = "typename")]
    [JsonKnownType(typeof(AliveMessage), "ContikiNgAlive")]
    [JsonKnownType(typeof(DaoMessage), "ContikiNgDao")]
    [JsonKnownType(typeof(SensorMessage), "ContikiNgSensors")]
    [JsonKnownType(typeof(BeaconMessage), "ContikiNgBeacon")]
    [JsonKnownType(typeof(TestUdpMessage), "ContikiNgTestUdp")]
    [JsonKnownType(typeof(BeaconListMessage), "ContikiNgBeaconList")]
    [JsonKnownType(typeof(UpstreamData), "UPSTREAMDATA")]
    public abstract class RawMessageBase
    {

    }

I have also seen that the upgrade to 0.4.1 leads to other exceptions than in 0.4.0

[TestMethod]
        [ExpectedException(typeof(JsonReaderException))]
        public async Task HandleAsync_MalformedMessage_IsIgnored()
        {
            var bus = new Mock<IBus>();
            var handler = new MessageStreamHandler(bus.Object);
            await handler.HandleAsync("{\"hello\": \"world\"");
            bus.VerifyNoOtherCalls();
        }

^^ This test is correct on 0.4.0, but in 0.4.1 it throws JsonSerializationException instead.

We ended up downgrading to 0.4.0 which works fine. Just want to let you know that your latest fixes is not tested properly.

dmitry-bym / JsonKnownTypes

Could not create an instance of type x Type is an interface or abstract class and cannot be instantiated. #17