XamlParseException when using ExpressionDark in Silverlight

I am currently using the ExpressionDark theme in a Silverlight project I am working on. I am having an issue where it throws an exception when I debug.

A first chance exception of type 'System.Windows.Markup.XamlParseException' occurred in System.Windows.dll

Additional information: Invalid attribute value dataForm:DataForm for property TargetType. [Line: 1 Position: 233]

This doesn't really affect anything because it still works fine, its just annoying. Here is a co开发者_JAVA百科de example.

<UserControl x:Class="MyProject.Controls.Test"
    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"
    xmlns:expressionDark="clr-namespace:System.Windows.Controls.Theming;assembly=System.Windows.Controls.Theming.ExpressionDark" 
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">
    <expressionDark:ExpressionDarkTheme ApplyMode="Auto" Background="#00000000">
        <Grid x:Name="LayoutRoot" Background="#00000000">
        </Grid>
    </expressionDark:ExpressionDarkTheme>
</UserControl>

If I comment out the expressionDark lines the exception goes away. Any idea on how to fix the exception or ignore it somehow?

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The needed reference has not been added for the DataForm within the consuming assembly.

Add a reference to the System.Windows.Controls.Data.DataForm assembly. If you need to make use of the DataForm within the UserControl explicitly you can define a namespace.

    xmlns:dataControls="clr-namespace:System.Windows.Controls;
assembly=System.Windows.Controls.Data.DataForm"