[Solved] Ajax async postback end does not work Script Error : Uncaught Sys.ScriptLoadFailedException: Sys.ScriptLoadFailedException: The script failed to load. Check for: Inaccessible path. Script errors. (IE) Enable 'Display a notification about every script error' under advanced settings. Missing call to Sys.Application.notifyScriptLoaded().

Solution For ajax async postback end does not work

 <script type="text/javascript">  
      function pageLoad(sender, args) {  
        //$(document).ready(function () {  
        Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(beginReq);  
        Sys.WebForms.PageRequestManager.getInstance().add_endRequest(endReq);  
        Sys.Browser.WebKit = {}; //Safari 3 is considered WebKit  
        if (navigator.userAgent.indexOf('WebKit/') > -1) {  
          Sys.Browser.agent = Sys.Browser.WebKit;  
          Sys.Browser.version = parseFloat(navigator.userAgent.match(/WebKit\/(\d+(\.\d+)?)/)[1]);  
          Sys.Browser.name = 'WebKit';  
        }  
        var xPos, yPos;  
        function beginReq(sender, args) {  
          //  $find(ModalPopup).show();  
        }  
        function endReq(sender, args) {  
          //  $find(ModalPopup).hide();  
        }  
        //});  
      }  
 </script>  

Use this script inside the page. :)