title: Visual Studio extension could not find a required assembly
body: <p>I wrote an extension for Visual Studio 2013. Because of <a href="https://stackoverflow.com/questions/7800032/cancel-combobox-selection-in-wpf-with-mvvm">bloody ComboBox bug</a>, I had to include System.Windows.Interactivity to my project. To add more details:</p>
  
  <ol>
  <li>&lt;Project&gt; uses additional solution assembly, say &lt;Project&gt;.Editor, which contains the physical editor.</li>
  <li>&lt;Project&gt;.Editor references System.Windows.Interactivity</li>
  <li>&lt;Project&gt; references System.Windows.Interactivity as well. In fact, I'm using nuget to load <em>Expression.Blend.Sdk</em> package (it's compatible with WPF 4.5)</li>
  </ol>
  
  <p>Effect: When part of editor, which contains mentioned <code>ComboBox</code> displays, I immediately get an exception:</p>
  
  <blockquote>
    <p>A first chance exception of type 'System.Windows.Markup.XamlParseException' occurred in PresentationFramework.dll</p>
    
    <p>Additional information: Could not load file or assembly 'System.Windows.Interactivity, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.</p>
  </blockquote>
  
  <p>I'm running the extension in the experimental instance and the folder:</p>
  
  <pre><code>C:\Users\&lt;user&gt;\AppData\Local\Microsoft\VisualStudio\12.0Exp\Extensions\&lt;Company&gt;\&lt;Extension&gt;\1.0
  </code></pre>
  
  <p>contains System.Windows.Interactivity.dll, but for some reason it seems not to be seen by the IDE.</p>
  
  <p>What's even more weird, I'm using other additional packages, like IronPython and they never caused me such trouble.</p>
  
  <p>How can I fix that?</p>
  
  <p><hr />
  <strong>Edit:</strong> In response to comments</p>
  
  <p>Actually, the InnerException contains field called <code>FusionLog</code>, which contains the following:</p>
  
  <pre><code>=== Pre-bind state information ===
  LOG: DisplayName = System.Windows.Interactivity, PublicKeyToken=31bf3856ad364e35
   (Partial)
  WRN: Partial binding information was supplied for an assembly:
  WRN: Assembly Name: System.Windows.Interactivity, PublicKeyToken=31bf3856ad364e35 | Domain ID: 1
  WRN: A partial bind occurs when only part of the assembly display name is provided.
  WRN: This might result in the binder loading an incorrect assembly.
  WRN: It is recommended to provide a fully specified textual identity for the assembly,
  WRN: that consists of the simple name, version, culture, and public key token.
  WRN: See whitepaper http://go.microsoft.com/fwlink/?LinkId=109270 for more information and common solutions to this issue.
  LOG: Appbase = file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/
  LOG: Initial PrivatePath = NULL
  Calling assembly : (Unknown).
  ===
  LOG: This bind starts in default load context.
  LOG: Using application configuration file: C:\Users\&lt;user&gt;\AppData\Local\Temp\devE4FC.tmp
  LOG: Using host configuration file: 
  LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.
  LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind).
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/System.Windows.Interactivity/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PublicAssemblies/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PublicAssemblies/System.Windows.Interactivity/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PrivateAssemblies/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PrivateAssemblies/System.Windows.Interactivity/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/CommonExtensions/Microsoft/TemplateProviders/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/CommonExtensions/Microsoft/TemplateProviders/System.Windows.Interactivity/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/CommonExtensions/Platform/Debugger/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/CommonExtensions/Platform/Debugger/System.Windows.Interactivity/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PrivateAssemblies/DataCollectors/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PrivateAssemblies/DataCollectors/System.Windows.Interactivity/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PrivateAssemblies/DataCollectors/x86/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PrivateAssemblies/DataCollectors/x86/System.Windows.Interactivity/System.Windows.Interactivity.DLL.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/System.Windows.Interactivity/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PublicAssemblies/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PublicAssemblies/System.Windows.Interactivity/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PrivateAssemblies/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PrivateAssemblies/System.Windows.Interactivity/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/CommonExtensions/Microsoft/TemplateProviders/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/CommonExtensions/Microsoft/TemplateProviders/System.Windows.Interactivity/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/CommonExtensions/Platform/Debugger/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/CommonExtensions/Platform/Debugger/System.Windows.Interactivity/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PrivateAssemblies/DataCollectors/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PrivateAssemblies/DataCollectors/System.Windows.Interactivity/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PrivateAssemblies/DataCollectors/x86/System.Windows.Interactivity.EXE.
  LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 12.0/Common7/IDE/PrivateAssemblies/DataCollectors/x86/System.Windows.Interactivity/System.Windows.Interactivity.EXE.
  </code></pre>
  
  <p>But there's more. I used ProcMon to check, where Visual Studio looks for that DLL and noticed in the end:</p>
  
  <pre><code>08:46:46,7508050    devenv.exe  7544    CreateFile  C:\Users\&lt;user&gt;\AppData\Local\Microsoft\VisualStudio\12.0Exp\Extensions\&lt;Company&gt;\&lt;Extension&gt;\1.0\Lib\System.Windows.Interactivity  NAME NOT FOUND  Desired Access: Read Attributes, Disposition: Open, Options: Open Reparse Point, Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a
  08:46:46,7509231    devenv.exe  7544    CreateFile  C:\Users\&lt;user&gt;\AppData\Local\Microsoft\VisualStudio\12.0Exp\Extensions\&lt;Company&gt;\&lt;Extension&gt;\1.0\Lib\System.Windows.Interactivity.EXE  NAME NOT FOUND  Desired Access: Read Attributes, Disposition: Open, Options: Open Reparse Point, Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a
  08:46:46,7510379    devenv.exe  7544    CreateFile  C:\Users\&lt;user&gt;\AppData\Local\Microsoft\VisualStudio\12.0Exp\Extensions\&lt;Company&gt;\&lt;Extension&gt;\1.0\Lib\System.Windows.Interactivity.DLL  NAME NOT FOUND  Desired Access: Read Attributes, Disposition: Open, Options: Open Reparse Point, Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a
  </code></pre>
  
  <p>The Lib folder contains a few Python modules I'm using (for scripting purposes, as I'm using IronPython). And, ironically, the assembly is in the </p>
  
  <pre><code>C:\Users\&lt;user&gt;\AppData\Local\Microsoft\VisualStudio\12.0Exp\Extensions\&lt;Company&gt;\&lt;Extension&gt;\1.0\
  </code></pre>
  
  <p>folder (without Lib). But Visual Studio omits it in its search despite fact, that it's the most natural place to search (as requesting assembly resides there as well)</p>