Run output sometimes "null" (and no status) about dispatch HOT 4 CLOSED

$ dispatch get runs node-hello-subscribe-4899 --json
[
    {
        "blocking": true,
        "executedTime": 1513365016,
        "finishedTime": -62135596800,
        "functionId": "3e7b1b8b-252d-4169-8aca-7c0fe8d5e246",
        "functionName": "node-hello-subscribe-4899",
        "input": {
            "name": "Jon",
            "place": "Winterfell"
        },
        "logs": null,
        "name": "c1bc3a36-a26c-4433-a19f-fbee9773c80f",
        "reason": [
            "error running function: node-hello-subscribe-4899: Server returned unexpected status code: 500 - Can't reach service: of-3e7b1b8b-252d-4169-8aca-7c0fe8d5e246"
        ],
        "secrets": null,
        "status": "ERROR"
    }
]