When the Lightweight render mode is enabled and you set large text in any of the dialogs of RadWindow, part of the text appears outside of the window. You can workaround this issue by overriding the styles of the dialogs. Below you can check a possible approach for RadAlert: <style type="text/css"> div.RadWindow { overflow: auto; height: auto !important; } .rwDialogMessage { padding-bottom: 30px; } </style>
This behavior is expected. If you do not provide dimensions to the radalert() method, there are some default values, so the best approach is to provide proper dimensions. Since text does not create flow (which makes it impossible to autosize the dialog based on text), it will go out of the dialog. The following article explains the most common problems and the requirements for autosizing: http://docs.telerik.com/devtools/aspnet-ajax/controls/window/troubleshooting/autosizing-issues You can read more about this case in the following thread: http://www.telerik.com/forums/radalert-with-autosize. While the CSS above may help, it is also likely to break the appearance/positioning of any RadWindow on the page.