I created a simple Silverlight 3 app.
<UserControl x:Class="SilverlightApplication2.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/2006"
mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480">
<Grid x:Name="LayoutRoot">
<TextBlock Text="Hello World!" ></TextBlock>
</Grid>
</UserControl>
When I run it I get this error
Line: 56
Error: Unhandled Error in Silverlight Application
Code: 2104
Category: InitializeError
Message: Could not download the Silverlight application. Check web server settings
Well if you look in the ClientBin folder you will see it is empty so the xap file is not available to be used
To fix this right click on the web application and select Build Order. On the Dependencies tab make sure the Checkbox next to the Silverlight app is checked.
