How to get rid of that HTML error report in ASP.NET MVC?

All I need would be just the error message in plain text. But ASP.NET is doing some HTML report output from every error.

I have a jquery ajax call and when an error is thrown I'm getting all that crap over to the client side.

I've created a filter attribute but didn't helped.

public class ClientErrorHandler : FilterAttribute, IExceptionFilter
{
    public void OnException(ExceptionContext filterContext)
    {
        var responce = filterContext.RequestContext.HttpContext.Response;
        responce.Write(filterContext.Exception.Message);
        responce.ContentType = MediaTypeNames.Text.Plain;
        filterContext.ExceptionHandled = true;
    }
}

EDIT

I'm seeing this

and I'd like to see just what is in here filterContext.Exception.Message