Sys.WebForms.PageRequestManagerParserErrorException: The message received from the server could not be parsed

I have a grid view on my page and I want to export it to the Excel Sheet, Below is the code I had written to do this task, here I am already passing the dataset to the method to bind the grid and btnExcelExport is the button which will export the Grid Content in to Excel Sheet :-

private void BindGridView(DataSet ds)
{
    if (ds.Tables.Count > 0)
    {
        if (ds.Tables[0].Rows.Count > 0)
        {
            GVUserReport.DataSource = ds;
            GVUserReport.DataBind();
            btnExcelExport.Visible = true;
        }
    }
}

protected void btnExcelExport_Click(object sender, EventArgs e)
{
    Response.Clear();
    Response.AddHeader("content-disposition","attachment;filename=FileName.xls");
    Response.Charset = "";
    Response.Cache.SetCacheability(HttpCacheability.NoCache);
    Response.ContentType = "application/vnd.xls";
    System.IO.StringWriter stringWrite = new System.IO.StringWriter();
    System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);
    GVUserReport.RenderControl(htmlWrite);
    Response.Write(stringWrite.ToString());
    Response.End();
}

public override void VerifyRenderingInServerForm(Control control)
{
    return;
}

Now when I am debugging I found that the grid is binded sucessfully but when trying to export it to Excel, I'm getting this error:

"Microsoft JScript runtime error: Sys.WebForms.PageRequestManagerParserErrorException: The message received from the server could not be parsed."

I fixed this issue. As I'm using UpdatePanel, I added below code in the Page_Load event of the page and it worked for me:

protected void Page_Load(object sender, EventArgs e) {
  ScriptManager scriptManager = ScriptManager.GetCurrent(this.Page);
  scriptManager.RegisterPostBackControl(this.btnExcelExport);
  //Further code goes here....
}

In my case, the problem was caused by some Response.Write commands at Master Page of the website (code behind). They were there only for debugging purposes (that's not the best way, I know)...

I added the control to the Triggers tag in the update panel:

    </ContentTemplate>
    <Triggers>
        <asp:PostBackTrigger ControlID="exportLinkButton" />
    </Triggers>
</asp:UpdatePanel>

This way the exportLinkButton will trigger the UpdatePanel to update.
More info here.