radwindow not showing content

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I have radbutton on CommandItemTemplate of radgrid and I have put the radgrid inside the update panel. once I clicked on the radbutton it suppose to pop up the radwindow with content. But in my case it is showing up the radwindow but content inside radwindow  is not loading. But If I remove the update panel, radwindow loads with correct content. I am not sure why adding update panel is not showing content on radwindow pop up.  Can you please provide some help on this?

Thanks