title: Unknown Build Error using WPF Toolkit
body: <p>I installed the Feb 2010 WPF Toolkit as I'm interested in evaluating the AutoCompleteBox control and I'm having extremely limited success. I can get the control to work, but as soon as I try and set any of it's properties in XAML, I get the following:</p>
  
  <p><em>Unknown build error, 'Cannot resolve dependency to assembly 'WPFToolkit, Version=3.5.40128.1, Culture=neutral, PublicKeyToken=31bf3856ad364e35' because it has not been preloaded. When using the ReflectionOnly APIs, dependent assemblies must be pre-loaded or loaded on demand through the ReflectionOnlyAssemblyResolve event.</em></p>
  
  <p>I've been testing this on a blank WPF window in a new solution. I'm guessing I'm just missing a reference or something... Here's the XAML (I've added nothing to the .xaml.cs):</p>
  
  <pre><code>&lt;Window x:Class="WpfToolkitApplication.Window1"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:toolkit="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Input.Toolkit"
      Title="Window1" Height="300" Width="300"&gt;
      &lt;Grid&gt;
          &lt;toolkit:AutoCompleteBox Height="25"/&gt;
      &lt;/Grid&gt;
  &lt;/Window&gt;
  </code></pre>
  
  <p>The only reference I've added is System.Windows.Controls.Input.Toolkit. Any ideas?</p>