Html page not showing up in .chm built using Sandcastle Help File Builder

With earlier version of SHFB (1.9.3.0) I am able to add the 'WhatsNew' html page content. The single html file shows up under contents See image

Below is the tag in .shbproj to add the html page

<ItemGroup>
    <Content Include="WhatsNew.html" />
</ItemGroup>

Following are settings that I am using when running with the latest SHFB version.

<HelpFileFormat>HtmlHelp1</HelpFileFormat>
<SyntaxFilters>Standard</SyntaxFilters>
<PresentationStyle>VS2013</PresentationStyle>
<CleanIntermediates>True</CleanIntermediates>
<KeepLogFile>True</KeepLogFile>
<DisableCodeBlockComponent>False</DisableCodeBlockComponent>

When built with the latest version of sandcastle help file builder I am no longer able to add the html page in the chm. I do not see any build errors or any warnings related to the html content. Any idea what I may be missing?