private void RenderPageCallback(HtmlTextWriter writer, Control pageControl)
...{
    AjaxFileUploadUtility.WriteScriptBlock(this.Page.Response, true);

    StringBuilder sb = new StringBuilder();
    HtmlTextWriter innerWriter = new HtmlTextWriter(new StringWriter(sb));
    renderPageCallbackMethodInfo.Invoke(        this.PageRequestManager, new object[] ...{ innerWriter, pageControl });

    writer.Write(sb.Replace("*/", "*//*").ToString());

    AjaxFileUploadUtility.WriteScriptBlock(this.Page.Response, false);
}

private void Page_Error(object sender, EventArgs e)
...{
    AjaxFileUploadUtility.WriteScriptBlock(this.Page.Response, true);

    onPageErrorMethodInfo.Invoke(this.PageRequestManager, new object[] ...{ sender, e });

    AjaxFileUploadUtility.WriteScriptBlock(this.Page.Response, false);
}