title: Mvc does not exist in the namespace system.web
body: <p>I am using Visual Studio 2017 and getting this error:</p>
  
  <blockquote>
    <p>The type or namespace name 'Mvc' does not exist in the namespace 'System.Web' (are you missing an assembly reference?)</p>
  </blockquote>
  
  <p>on this line of code:</p>
  
  <pre><code>using System.Web.Mvc;
  </code></pre>
  
  <p>that using is needed for resolving <code>SelectListItem</code> on this line of code:</p>
  
  <pre><code>public static List&lt;SelectListItem&gt; VerificationMethod
  </code></pre>
  
  <p>I would expect adding an assembly reference would easily solve the problem.</p>
  
  <p>Here is what I tried....</p>
  
  <p>I tried adding an assembly reference by right clicking on the project and selecting <code>Add -&gt; Reference</code>.  <code>System.Web.Mvc</code> was not in the list of references to add.</p>
  
  <p>Some other SO posts referenced package <code>Microsoft.Aspnet.Mvc</code> as resolving this.  That package was not available either.</p>
  
  <p>I tried this on the nuget console:</p>
  
  <pre><code>PM&gt; Install-Package System.Web.mvc
  Install-Package : Unable to find package 'System.Web.mvc'
  At line:1 char:1
  + Install-Package System.Web.mvc
  + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  + CategoryInfo          : NotSpecified: (:) [Install-Package], Exception
  + FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PackageManagement.PowerShellCmdlets.InstallPackageCommand
  </code></pre>
  
  <p>I also tried this:</p>
  
  <pre><code>PM&gt; Install-Package Microsoft.aspnet.mvc
  Package 'Microsoft.aspnet.mvc.5.2.6' already exists in project 'MySite'
  Time Elapsed: 00:00:00.0549251
  PM&gt; 
  </code></pre>
  
  <p>I also tried this:</p>
  
  <pre><code>update-package -reinstall Microsoft.AspNet.Mvc
  </code></pre>
  
  <p>And got this error:</p>
  
  <blockquote>
    <p>Install failed. Rolling back...<br>
    Package 'EntityFramework 6.1.0' does not exist in project 'DataAccess'</p>
  </blockquote>