title: CS0234: The type or namespace name 'Description' does not exist in the namespace 'System.Web.Http' (are you missing an assembly reference?)
body: <p>I'm having namespaces error in ASP.Net MVC WebAPI.
  I'm using MVC 4 with .Net Framework 4.5, while running the application It works but on the click of API it displays error like below.</p>
  
  <pre><code>    ------------------------------------------------------------------------------------
      Server Error in '/' Application.
  
      Compilation Error
  
      Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.
  
      Compiler Error Message: CS0234: The type or namespace name 'Description' does not exist in the namespace 'System.Web.Http' (are you missing an assembly reference?)
  
      Source Error:
      Line 1:  @using System.Web.Http
      Line 2:  @using System.Web.Http.Description
      Line 3:  @using System.Collections.ObjectModel
      Line 4:  @using SmartCare360APIs.Areas.HelpPage.Models
  
      Source File: e:\Projects\SmartCare 360\Code\SmartCare360APIs\SmartCare360APIs\Areas\HelpPage\Views\Help\Index.cshtml    Line: 2
  
      Show Detailed Compiler Output:
      Show Complete Compilation Source:
  
      Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.6.1637.0
      -----------------------------------------------------------------------------------
  </code></pre>
  
  <p>Below is the where namespace is missing.
      I tried to reinstall mvc 4 but it comes with many more error.</p>
  
  <pre><code>Page : **ApiGroup.cshtml**
  
   @using System.Web.Http
   @using System.Web.Http.Description
   @using SmartCare360APIs.Areas.HelpPage
   @using SmartCare360APIs.Areas.HelpPage.Models
   @model IGrouping&lt;string, ApiDescription&gt;
  
   &lt;h2 id="@Model.Key"&gt;@Model.Key&lt;/h2&gt;
   &lt;table class="help-page-table"&gt;
   &lt;thead&gt;
                  &lt;tr&gt;&lt;th&gt;API&lt;/th&gt;&lt;th&gt;Description&lt;/th&gt;&lt;/tr&gt;
              &lt;/thead&gt;
              &lt;tbody&gt;
              @foreach (var api in Model)
              {
                  &lt;tr&gt;
                      &lt;td class="api-name"&gt;&lt;a href="@Url.Action("Api", "Help", new { apiId = api.GetFriendlyId() })"&gt;@api.HttpMethod.Method @api.RelativePath&lt;/a&gt;&lt;/td&gt;
                      &lt;td class="api-documentation"&gt;
                      @if (api.Documentation != null)
                      {
                          &lt;p&gt;@api.Documentation&lt;/p&gt;
                      }
                      else
                      {
                          &lt;p&gt;No documentation available.&lt;/p&gt;
                      }
                      &lt;/td&gt;
                  &lt;/tr&gt;
              }
              &lt;/tbody&gt;
          &lt;/table&gt;
  </code></pre>