Can't able to Run the basic Silverlight application

When I try to run a simple, basic Silverlight application, I got the following error:

Can't find the TestPage.html, Make sure the path or internet address is correct.

Here is my XAML code:

<UserControl x:Class="HelloWorld.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility开发者_高级运维/2006" 
    mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480">
  <Grid x:Name="LayoutRoot" Background="White">
        <TextBlock Text="Hello, World!" />    
  </Grid>
</UserControl>

What could be the reason for this? Any help would be greatly appreciated.

Thanks.

---

This sounds like an issue with your project setup. Make sure your ASP.NET project is correctly set with your Silverlight project as a contained Silverlight app. Also you will want to check that in the Project Properties the Startup Item is set to an existing page. It may not be TestPage.html.