NUnit failed to load DLL
<p>I am getting the following error message when trying to run unit tests in Visual Studio:</p>

<pre><code>NUnit failed to load w:\Repos\trading.tools\Trading.Tools.Test\bin\x64\Debug\Trading.Tools.Test.dll
</code></pre>

<p>I am using</p>

<ul>
<li>Visual Studio Community 2013</li>
<li>NUnit Adapter 3.4.0.0</li>
<li>NUnit 3.4.1</li>
</ul>

<p>The weird thing is, that I have another project which is set up the same way as this one and it works just fine.</p>

<p>I also downloaded NUnit 3.4.1 and installed it. When I run </p>

<pre><code>nunit3-console.exe Trading.Tools.Test.dll
</code></pre>

<p>everything works just fine.
Any ideas what I can do?</p>

<p>Many thanks
Konstantin</p>

<p><strong>Edit #1</strong></p>

<p>Here is the full console output from Visual Studio when trying to run all test.</p>

<pre><code>Test run will use DLL(s) built for framework Framework45 and platform X86. Following DLL(s) will not be part of run: 
Trading.Tools.Test.dll, Trading.Tools.dll are built for Framework Framework45 and Platform X64.
 Go to http://go.microsoft.com/fwlink/?LinkID=236877&amp;clcid=0x409 for more details on managing these settings.
NUnit Adapter 3.4.0.0: Test discovery starting
NUnit failed to load w:\Repos\trading.tools\Trading.Tools.Test\bin\x64\Debug\Trading.Tools.Test.dll
Assembly contains no NUnit 3.0 tests: w:\Repos\trading.tools\Trading.Tools\bin\x64\Debug\Trading.Tools.dll
NUnit Adapter 3.4.0.0: Test discovery complete
</code></pre>

<p>As you can see it is very obvious that NUnit expects a x86 build, but I build for a x64 platform. And again, my x64 build works just fine if I execute it using <code>nunit3-console.exe</code>.</p>

<p>What I see in the <code>csproj</code> file is this:</p>

<pre><code>&lt;Reference Include="nunit.framework, Version=2.6.4.14350, Culture=neutral, PublicKeyToken=96d09a1eb7f44a77, processorArchitecture=MSIL"&gt;
  &lt;SpecificVersion&gt;False&lt;/SpecificVersion&gt;
  &lt;HintPath&gt;..\packages\NUnit.3.4.1\lib\net45\nunit.framework.dll&lt;/HintPath&gt;
&lt;/Reference&gt;
</code></pre>

<p>The weird thing here is that it specifies using <code>Version=2.6.4.14350</code> but referencing a 3.4.1 dll.</p>

<p>So the next question from this point is how can I make NUnit execute my x64 build? Any ideas?</p>