Hi all,
I used the following methods to disable my page when an ajax request begins. The page enables when the request ends. It works perfectly in all browsers except IE11. A javascript error "JavaScript runtime error: Unable to get property 'PageRequestManager' of undefined or null reference" happened when the page loads. 
function InitializeScriptManager() { Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(BeginRequestHandler); Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler); } function BeginRequestHandler(sender, args) { parent.DisablePage(); } function EndRequestHandler(sender, args) { parent.EnablePage(); parent.SetFrameHeight(); } Does any hotfixes are available for the issue? Thanks in advance.
Binoj KN

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