Closed Issue: version changed to 4.1.60501.0 ,cause error on IE8, not happened on previous version [27165]

Hi ,I have changed ajaxcontroltoolkit to 4.1.60501.0, the it shows error like the attachment on IE 8 ( not in IE9 , IE9 (mode IE8),firefox,chrome)
Comments: Please upgrade to the latest version of AJAX Control Toolkit v15.1. If the problem remains, feel free to post a new issue.