SceneController: ActivationStarted response "Sorry ... is not responding"

[matespi]

The scene is correctly added and activated, but the response to the activation directive (ActivationStarted) returns "400 malformed". Currently the reply json is sent asynchronously and is as follows:

{
    "context": {
        "properties": [
            {
                "uncertaintyInMilliseconds": 200,
                "name": "connectivity",
                "timeOfSample": "<time>",
                "value": {
                    "value": "OK"
                },
                "namespace": "Alexa.EndpointHealth"
            }
        ]
    },
    "event": {
        "endpoint": {
            "scope": {
                "token": "<AccessToken>",
                "type": "BearerToken"
            },
            "endpointId": "Scene-Id"
        },
        "header": {
            "messageId": "abc-123-def-456",
            "correlationToken": "<correlation-toke n>",
            "payloadVersion": "3",
            "namespace": "Alexa.SceneController",
            "name": "ActivationStarted"
        },
        "payload": {
            "timestamp": "<time>",
            "cause": {
                "type": "VOICE_INTERACTION"
            }
        }
    }
}

I read that the SceneController interface does not support deferred response here, so currently the skill does not return anything synchronously. I am pretty sure the asynchronous response is sent within 5 seconds. The status code suggests that there is an error in the response json that I can't find comparing it with the documentation here. Can anyone help me find what im missing?

[aszk]

Can I get the actual response you sent? I assume time stamp format might be wrong. You need to follow ISO 8601 timestamp format. I also need to mention that context should be empty.

[aszk]

Closing due to inactivity.