You encountered the following error at run-time:
The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).
ZeeControls inserts default style sheets to the <head> section of the page. If there is any code block (i.e. <% ... %>) in the <head> section, the above exception will be thrown when the default style sheets are inserted. Please move the code block outside of the <head> section.
For example, you might want to declare an OnClientPanelResized event handler, and use <%= Panel.ClientID %> to get the panel's ID. The following declaration will generate the above exception.
<head runat="server">
<title>My App</title>
<script type="text/javascript">
function PanelResizedHandler (panelId, oldWidth, oldHeight, newWidth, newHeight) {
if (panelId == '<%= TreeviewPanel.ClientID %>') {
ResizeTreeview(newWidth, newHeight);
}
}
</script>
</head>
The remedy is to move the function declaration to the start of <body> section.