Does anyone have any suggestions?
The error above occurs when this code is executed:
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(RequestCompleted);
Specifically within this section:
<script language="javascript" type="text/javascript">
var postBackElement;
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(RequestCompleted);
Sys.WebForms.PageRequestManager.getInstance().add_initializeRequest(InitializeRequestHandler);
function InitializeRequestHandler(sender, args) {
//set the postBackElement
postBackElement = args.get_postBackElement();
}