I'm trying to display error messages from a SS service.

I'm throwing the following

 throw new ArgumentException("Somthing not right here!!!!");

And in my vue component the calling code is the following

    try {
       
        let request = new CreateUserVehicle();
        var response = await createUserVehicle(request);
        this.userVehicle = response.userVehicle;

    } catch (error) {
         console.log(error.responseStatus);
        this.responseStatus = error.responseStatus || error;
    }

the console log is only showing

ResponseStatus {errorCode: "400", message: "ArgumentException"}

How do I show the message that I am throwing in the service? I've tried looking at the techstacks project but can't figure out how it is done.

Does the raw HTTP Response Headers contain the structured Error Response?

No it doesn't appear so,

HTTP/1.1 400 ArgumentException
content-type: application/json; charset=utf-8
vary: Accept
server: Kestrel
access-control-allow-credentials: true
access-control-allow-headers: Content-Type, Allow, Authorization
access-control-allow-methods: GET, POST, PUT, DELETE, PATCH, OPTIONS
access-control-allow-origin: *
x-powered-by: ServiceStack/5.11 NETStandard/.NET, ASP.NET
x-sourcefiles: =?UTF-8?B?QzpcRGV2XEFzcFN1cHBvcnRcQXNwU3VwcG9ydFxBc3BTdXBwb3J0XGpzb25ccmVwbHlcVXBkYXRlVXNlclZlaGljbGU=?=
date: Wed, 18 Jul 2018 19:19:39 GMT
connection: close
Content-Length: 20

{"userVehicle":null}

If you're using a {Request}Response convention for your Response DTO it needs a ResponseStatus property, see docs for more info:

http://docs.servicestack.net/error-handling#error-response-types