title: ASP.NET MVC 5 an error occurs when calling the *.less in windows Azure
body: <p>I have a project in "ASP.NET MVC 5" and use "less" for files "bootstrap", use the following libraries:</p>
  
  <p><a href="http://www.nuget.org/packages/BundleTransformer.Core/" rel="nofollow">http://www.nuget.org/packages/BundleTransformer.Core/</a>
  <a href="http://www.nuget.org/packages/BundleTransformer.Less/" rel="nofollow">http://www.nuget.org/packages/BundleTransformer.Less/</a>
  <a href="http://www.nuget.org/packages/JavaScriptEngineSwitcher.Core/" rel="nofollow">http://www.nuget.org/packages/JavaScriptEngineSwitcher.Core/</a>
  <a href="http://www.nuget.org/packages/JavaScriptEngineSwitcher.Msie/" rel="nofollow">http://www.nuget.org/packages/JavaScriptEngineSwitcher.Msie/</a>
  <a href="http://www.nuget.org/packages/MsieJavaScriptEngine/" rel="nofollow">http://www.nuget.org/packages/MsieJavaScriptEngine/</a></p>
  
  <p>in my BundleConfig.css I have this:</p>
  
  <pre><code>BundleTable.EnableOptimizations = false;
  bundles.UseCdn = true;
  CssTransformer cssTransformer = new CssTransformer();
  JsTransformer jsTransformer = new JsTransformer();
  NullOrderer nullOrderer = new NullOrderer();
  
  Bundle cssBundle = new CustomStyleBundle("~/bundles/css");
  cssBundle.Include("~/Content/bootstrap/bootstrap.less");
  cssBundle.Include("~/Content/font-awesome.css");
  cssBundle.Include("~/Content/site.less");
  cssBundle.Transforms.Add(cssTransformer);
  cssBundle.Orderer = nullOrderer;
  bundles.Add(cssBundle);
  </code></pre>
  
  <p>in my environment works fine and if I use IIS works fine, but when I make the publush in "Windows Azure" for "less" files get this error:</p>
  
  <pre><code>HTTP/1.1 500 Internal Server Error
  Content-Length: 75
  Content-Type: text/html
  Server: Microsoft-IIS/8.0
  X-Powered-By: ASP.NET
  Date: Wed, 21 May 2014 11:56:01 GMT
  
  The page cannot be displayed because an internal server error has occurred.
  </code></pre>
  
  <p>Only with files less, others file like css o js return rigth</p>
  
  <p>(I think I have another problem that does not display errors but that's another question). Web.config for error:</p>
  
  <pre><code>&lt;system.web&gt;
  
      &lt;customErrors mode="Off"&gt;
      &lt;/customErrors&gt;
  </code></pre>
  
  <p><strong>edit</strong></p>
  
  <p>configuration for less in web.config like <a href="http://visualstudiogallery.msdn.microsoft.com/5ed81082-fc81-458a-a30c-0d15b6e8386f" rel="nofollow">this template</a></p>
  
  <pre><code>&lt;bundleTransformer xmlns="http://tempuri.org/BundleTransformer.Configuration.xsd"&gt;
  
    &lt;less&gt;
      &lt;jsEngine name="MsieJsEngine" /&gt;
    &lt;/less&gt;
  
      &lt;core&gt;
          &lt;css&gt;
              &lt;minifiers&gt;
                  &lt;add name="NullMinifier" type="BundleTransformer.Core.Minifiers.NullMinifier, BundleTransformer.Core" /&gt;
              &lt;/minifiers&gt;
              &lt;translators&gt;
                  &lt;add name="NullTranslator" type="BundleTransformer.Core.Translators.NullTranslator, BundleTransformer.Core" enabled="false" /&gt;
              &lt;add name="LessTranslator" type="BundleTransformer.Less.Translators.LessTranslator, BundleTransformer.Less" /&gt;&lt;/translators&gt;
          &lt;/css&gt;
          &lt;js&gt;
              &lt;minifiers&gt;
                  &lt;add name="NullMinifier" type="BundleTransformer.Core.Minifiers.NullMinifier, BundleTransformer.Core" /&gt;
              &lt;/minifiers&gt;
              &lt;translators&gt;
                  &lt;add name="NullTranslator" type="BundleTransformer.Core.Translators.NullTranslator, BundleTransformer.Core" enabled="false" /&gt;
              &lt;/translators&gt;
          &lt;/js&gt;
  
      &lt;/core&gt;
  &lt;/bundleTransformer&gt;
  &lt;jsEngineSwitcher xmlns="http://tempuri.org/JavaScriptEngineSwitcher.Configuration.xsd"&gt;
    &lt;core&gt;
          &lt;engines&gt;
              &lt;add name="MsieJsEngine" type="JavaScriptEngineSwitcher.Msie.MsieJsEngine, JavaScriptEngineSwitcher.Msie" /&gt;
          &lt;/engines&gt;
      &lt;/core&gt;
  &lt;/jsEngineSwitcher&gt;
  </code></pre>