title: The requested script resource 'Compat.Timer.Timer.js' requires version 'AjaxControlToolkit'
body: <p>Currently I upgraded my 3.5 web site to 4.0 for better performance I upgraded AjaxToolkit 3.5 to 4.0. And i'm found this error like :</p>
  
  <blockquote>
    <p>Server Error in '/EasyWeb' Application.</p>
    
    <p>The requested script resource 'Compat.Timer.Timer.js' requires version
    'AjaxControlToolkit, Version=4.1.7.1213, Culture=neutral,
    PublicKeyToken=28f01b0e84b6d53e' of the ASP.NET AJAX Framework. To use
    this resource, make sure that the application references version
    'AjaxControlToolkit, Version=4.1.7.1213, Culture=neutral,
    PublicKeyToken=28f01b0e84b6d53e'.</p>
    
    <p>Description: An unhandled exception occurred during the execution of
    the current web request. Please review the stack trace for more
    information about the error and where it originated in the code. </p>
    
    <p>Exception Details: System.InvalidOperationException: The requested
    script resource 'Compat.Timer.Timer.js' requires version
    'AjaxControlToolkit, Version=4.1.7.1213, Culture=neutral,
    PublicKeyToken=28f01b0e84b6d53e' of the ASP.NET AJAX Framework. To use
    this resource, make sure that the application references version
    'AjaxControlToolkit, Version=4.1.7.1213, Culture=neutral,
    PublicKeyToken=28f01b0e84b6d53e'.</p>
    
    <p>Source Error: </p>
    
    <p>An unhandled exception was generated during the execution of the
    current web request. Information regarding the origin and location of
    the exception can be identified using the exception stack trace below.</p>
    
    <p>Stack Trace: </p>
    
    <p>[InvalidOperationException: The requested script resource
    'Compat.Timer.Timer.js' requires version 'AjaxControlToolkit,
    Version=4.1.7.1213, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e'
    of the ASP.NET AJAX Framework. To use this resource, make sure that
    the application references version 'AjaxControlToolkit,
    Version=4.1.7.1213, Culture=neutral,
    PublicKeyToken=28f01b0e84b6d53e'.]<br>
    System.Web.UI.ScriptReference.GetUrlInternal(ScriptManager
    scriptManager, Boolean zip) +469796<br>
    System.Web.UI.ScriptReference.GetUrl(ScriptManager scriptManager,
    Boolean zip) +213<br>
    System.Web.UI.ScriptManager.RegisterUniqueScripts(List`1
    uniqueScripts) +202    System.Web.UI.ScriptManager.RegisterScripts()
    +444    System.Web.UI.ScriptManager.OnPagePreRenderComplete(Object sender, EventArgs e) +122<br>
    System.Web.UI.Page.OnPreRenderComplete(EventArgs e) +8872106<br>
    System.Web.UI.Page.ProcessRequestMain(Boolean
    includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
    +2716 Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1</p>
  </blockquote>
  
  <p>What I have to do to fix it now?</p>