mvc error , I am getting this error while loading the site.master page of my website
<p>I am getting the following error while loading the <code>site.master</code> page of my website </p>

<p>Error:</p>

<p><code>Could not load file or assembly 'System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified. C:\TravelRequest_old\App_Themes\Aqua\MVCxPivotGrid.skin</code></p>

<p>I have uploaded the new <strong>dll</strong> file of <strong>syetem.web.mvc version 3</strong> in </p>

<p><code>C:\Program Files (x86)\Microsoft ASP.NET\ASP.NET MVC 3</code> and also added the reference from solution explorer.Then I am getting the following error</p>

<p>Error :</p>

<pre><code>Could not load file or assembly 'System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. 
Strong name signature could not be verified.  The assembly may have been tampered with, or it was delay signed but not fully signed with the correct private key. 
</code></pre>
