title: IIS Express Debugging No Longer Working
body: <p>I'm using IIS Express with Visual Studio 2013 on Windows 8.1 x64 for a WebAPI 2 application (all en-US here). This worked just fine roughly a month ago, but now I'm getting errors when attempting to debug the application.</p>
  
  <p>If I do not run VS as admin (again, didn't need to do this before), I get:</p>
  
  <pre><code>A first chance exception of type 'System.UnauthorizedAccessException' occurred in mscorlib.dll
  
  Additional information: Access to the path 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\~AspAccessCheck_c00414062044.tmp' is denied.
  </code></pre>
  
  <p>A second error occurs after this, or it will be the first error if I run VS as Administrator:</p>
  
  <pre><code>A first chance exception of type 'System.Globalization.CultureNotFoundException' occurred in mscorlib.dll
  
  Additional information: Culture is not supported.
  </code></pre>
  
  <p>If I run the same WebAPI application from WebMatrix 3, it runs without errors (with or without running 'as Admin').</p>
  
  <p>Project IIS config settings:</p>
  
  <pre><code>&lt;UseIISExpress&gt;true&lt;/UseIISExpress&gt;
  &lt;IISExpressSSLPort&gt;46435&lt;/IISExpressSSLPort&gt;
  &lt;IISExpressAnonymousAuthentication&gt;enabled&lt;/IISExpressAnonymousAuthentication&gt;
  &lt;IISExpressWindowsAuthentication&gt;disabled&lt;/IISExpressWindowsAuthentication&gt;
  &lt;IISExpressUseClassicPipelineMode&gt;false&lt;/IISExpressUseClassicPipelineMode&gt;
  </code></pre>
  
  <p>I also have the application running on <a href="http://localhost:46436" rel="nofollow">http://localhost:46436</a>.</p>
  
  <p>What I also find really strange is that the project properties show "IIS Express" and to use a URL of <a href="http://localhost:46436/" rel="nofollow">http://localhost:46436/</a>, but in the project file I'm seeing:</p>
  
  <pre><code>  &lt;ProjectExtensions&gt;
      &lt;VisualStudio&gt;
        &lt;FlavorProperties GUID="{349c5851-65df-11da-9384-00065b846f21}"&gt;
          &lt;WebProjectProperties&gt;
            &lt;UseIIS&gt;True&lt;/UseIIS&gt;
            &lt;AutoAssignPort&gt;True&lt;/AutoAssignPort&gt;
            &lt;DevelopmentServerPort&gt;46435&lt;/DevelopmentServerPort&gt;
            &lt;DevelopmentServerVPath&gt;/&lt;/DevelopmentServerVPath&gt;
            &lt;IISUrl&gt;http://localhost:46436&lt;/IISUrl&gt;
  </code></pre>
  
  <p>That may explain my access denied. Regardless if I unset, save, and re-set to use IIS Express (storing it for all users), the <code>&lt;UseIIS&gt;</code> property is set back to true.</p>
  
  <p>EDIT: It looks like "Use IIS" is normal. I created a new WebAPI 2 project as a test. It ran fine under IIS Express OOTB.</p>