I hope to use v8 for a new website, but even simple things seem out of order.

I just created this super simple template, or actually Umbraco created most of it from Create Document Type With Template and Insert Value. I only selected two values and wrapped them in h1 and p.

But ... preview displays the yellow pages (Server Error in '/' Application)

@inherits Umbraco.Web.Mvc.UmbracoViewPage<ContentModels.Page>
@using ContentModels = Umbraco.Web.PublishedModels;
@{
    Layout = "mainTemplate.cshtml";
}

<h1>@Model.Value("pageTitle")</h1>
<p>@Model.Value("pageSummary")</p>

How can this not work?