Hi ksanjay,
Please try the example below? Does it get the same issue?
<%@ Page Language="C#" Title="example" %>
<%@ 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">
<CuteWebUI:UploadAttachments runat="server" ID="UploadAttachments1">
</CuteWebUI:UploadAttachments>
</form>
</body>
</html>
If it works for you, then try remove the content form your page one by one to find out whihc section cause this issue.
If still get the same issue with the example below, please download the latest version to try again.
Latest version downloads http://ajaxuploader.com/download/Ajax-Uploader.zip
Regards,
Ken