title: Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies... The system cannot find the file specified
body: <p>I am getting an error on my ASPX file
  after register control toolkit then also not access <code>&lt;cc1:........&gt;</code>.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>&lt;%@ Page Language="C#" AutoEventWireup="true"
       CodeFile="DropdownlistCSC.aspx.cs" Inherits="DropdownlistCSC" %&gt; 
      &lt;%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %&gt;
  
  &lt;!DOCTYPE html&gt;
  </code></pre>
  
  <p>This is the error I am getting:</p>
  
  <blockquote>
    <p>Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies. The system cannot find the file specified.</p>
  </blockquote>