I've created a Visual Studio solution using the UaaS script according to https://our.umbraco.org/documentation/Umbraco-Cloud/Set-Up/Visual-Studio/.

I have created a very simple SurfaceController in the *.Core project but when running the web site locally I get "The controller for path '/' was not found or does not implement IController" when accessing a view that uses the controller. It's caused by @{ Html.RenderAction("RenderHeader", "My"); }

What have I missed?

MyController.cs

namespace CloudTest.Core.Controllers
{
    class MyController: SurfaceController
    {
        public ActionResult RenderHeader()
        {
            return PartialView("~/Views/Partials/_Header.cshtml");
        }
    }
}

_Header.cshtml

@inherits Umbraco.Web.Mvc.UmbracoTemplatePage
<div>
    This is the header area!
</div>

Test.cshtml

@inherits Umbraco.Web.Mvc.UmbracoTemplatePage
@using ContentModels = Umbraco.Web.PublishedContentModels;
@{
    Layout = null;
}
@{ Html.RenderAction("RenderHeader", "My"); }