I made a Silverlight project like this:
<UserControl x:Class="silverlighttest3.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" Height="270" Width="487">
<Grid x:Name="LayoutRoot" Background="blue" Height="270" Width="487" HorizontalAlignment="Stretch">
<MultiScaleImage HorizontalAlignment="Left" Margin="146,27,0,0" Name="multiScaleImage1" VerticalAlignment="Top" Source="Source/dzc_output.xml"/>
</Grid>
and after that I tested it and it worked just fine.
The problem is when testing the web Application that hosted the Silverlight project, when trying the 'testsilverlight.aspx' there is nothing shown.
Note: the source folder is in the Silverlight directory and not in the web application directory. and when copied it to web application directory the result is same - a white page.