What is error AjaxControlToolkit.CommonToolkitScripts ?

In asp.net application, check below ASP.NET HTML and Javascript code

Problem case:

<aspext:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server">
      <Scripts>
           <asp:ScriptReference Name="AjaxControlToolkit.Common.Common.js" Assembly="AjaxControlToolkit" />
           <asp:ScriptReference Name="AjaxControlToolkit.ExtenderBase.BaseScripts.js" Assembly="AjaxControlToolkit" />
      </Scripts>
</aspext:ToolkitScriptManager>
<asp:Panel ID="Panel1" runat="server" ClientIDMode="Static" />

<script type="text/javascript" language="javascript">
      function getPosition() {
           var commonObj = new AjaxControlToolkit._CommonToolkitScripts();
           $common.setBounds($get("Panel1"),
           {
                x : 100,
                y : 200,
                width : 200,
                height : 100
           }
      }
 </script>

The assembly 'AjaxControlToolkit, Version=4.1.40412.0, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e' does not contain a Web resource that has the name 'AjaxControlToolkit.Common.Common.js'. Make sure that the resource name is spelled correctly. Make sure that the application references the correct version of an ASP.NET AJAX Framework assembly

Possible Solution:

1. Try using ScriptManager instead of ToolkitScriptManager as below

<asp:ScriptManager ID="ScriptManager1" runat="server">
            <Scripts>
                <asp:ScriptReference Name="AjaxControlToolkit.Common.Common.js" Assembly="AjaxControlToolkit" />
                <asp:ScriptReference Name="AjaxControlToolkit.ExtenderBase.BaseScripts.js" Assembly="AjaxControlToolkit" />
            </Scripts>
</asp:ScriptManager>

2. Check the version of your ASP.NET application, because above scripts are for .NET 3.5 sp1 as mentioned here on www.asp.net.

Reference from my answer on StackOverflow