Slow closing RadWindow Lightweight rendering in Internet Explorer

2 posts, 0 answers
  1. Eric
    Eric avatar
    5 posts
    Member since:
    Dec 2013

    Posted 29 Aug 2016 Link to this post


    I am facing a performance issue when closing a radwindow Lightweight rendering in only IE browser (IE v11).

    I tried hiding the radwindow by using onClientBeforeClose client event to improve user experience BUT I got no lucky. The problem is still the same.

    Is there any way which can solve it or improve UX when closing the radwindow?

    function OnClientBeforeCloseHandler(sender, args) {
        if (sender && sender.get_popupElement() && sender.get_popupElement().style && $telerik.isIE) {
            sender.get_popupElement().style.display = "none";

  2. Marin Bratanov
    Marin Bratanov avatar
    4533 posts

    Posted 29 Aug 2016 Link to this post

    Hello Eric,

    This is not a known issue and apart from the idea you've already tried, I can suggest a few others:

    • try using setUrl("about:blank") in the OnClientBeforeClose handler
    • ensure IE is running in Edge mode (i.e., standards mode) and not in Compatibility mode or in IE10 mode. This can also be enforced with a <meta> tag and/or an HTTP header
    • review whether there is any additional code running (e.g., an AJAX request initiated by the OnClientClose handler, or by the code that called the RadWindow's close() method)
    • if a server request is closing the dialog, ensure you are using the Sys.Application.Load event to close the RadWindow, in a fashion similar to the approach used here
    • try setting the DestroyOnClose property to true in case the issue stems from the content page (test with a different, simple one to confirm) and the fact that closing the RadWindow merely hides it with CSS

    If neither helps, I advise that you open a support ticket and send us a small runnable example so we can investigate. 


    Marin Bratanov
    Telerik by Progress
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