Hi stephen_albert,
Please try the example below, does it work for you?
<%@ Page Language="C#" Title="Customize the queue UI" %>
<%@ Register TagPrefix="CuteWebUI" Namespace="CuteWebUI" Assembly="CuteWebUI.AjaxUploader" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
</head>
<body>
<form id="Form1" runat="server">
<div>
<CuteWebUI:UploadAttachments runat="server" ID="UploadAttachments1">
<ValidateOption MaxSizeKB="2000000" />
</CuteWebUI:UploadAttachments>
</div>
</form>
</body>
</html>
Regards,
Ken