have the following code to export and I get this error:
Code:

protected void RadScheduler1_AppointmentCommand(object sender, AppointmentCommandEventArgs e)

{

    if (e.CommandName == "Export")

    {

        WriteCalendar(

RadScheduler.ExportToICalendar(e.Container.Appointment));

     }

}

private

void WriteCalendar(string data)

{

HttpResponse response = Page.Response;

response.End();

response.Clear();

response.Buffer =

true;

response.ContentType =

"text/calendar";

response.ContentEncoding =

Encoding.UTF8;

response.Charset =

"utf-8";

response.AddHeader(

"Content-Disposition", "attachment;filename=\"RadSchedulerExport.ics\"");

response.Write(data);

response.End();

}

htm in the code:

function Export(sender, e)

{

$find(

"<%# RadAjaxManager1.ClientID %>").__doPostBack(sender.name, "");

}

<

telerik:RadScheduler ID="RadScheduler1" runat="server" Skin="Hay" StartInsertingInAdvancedForm="True"

OnAppointmentDelete="RadScheduler1_AppointmentDelete" OnAppointmentUpdate="RadScheduler1_AppointmentUpdate"

OnAppointmentInsert="RadScheduler1_AppointmentInsert" OnNavigationComplete="RadScheduler1_NavigationComplete"

Height="550px" Width="800px" CustomAttributeNames="Engagement,CodigoEmpleado"

OnAppointmentDataBound="RadScheduler1_AppointmentDataBound" ShowFooter="False"

DayStartTime="07:00:00" WorkDayEndTime="18:00:00" WorkDayStartTime="07:00:00"

OnAppointmentCreated="RadScheduler1_AppointmentCreated" OnFormCreating="RadScheduler1_FormCreating"

OnFormCreated="RadScheduler1_FormCreated" EnableDescriptionField="True" BorderStyle="Solid"

EnableCustomAttributeEditing="True" OnAppointmentCommand="RadScheduler1_AppointmentCommand">

<TimelineView UserSelectable="False" />

<AppointmentTemplate>

<span style="font-weight: bold; font-size: small">

<div>

<%

# Eval("Subject") %>

<asp:Button runat="server" ID="Button1" CssClass="rsExportButton" ToolTip="Exportar reserva"

CommandName="Export" OnClientClick="Export(this, event); return false;" Style="cursor: pointer;

cursor: hand;"

/>

</div>

</span>

<%

# Eval("Resources[0].text") %>

<div>

<%

# Eval("Resources[1].text")%>

</div>

</AppointmentTemplate>

<TimeSlotContextMenuSettings EnableDefault="True" />

<AppointmentContextMenuSettings EnableDefault="True" />

<AdvancedForm Modal="True" EnableCustomAttributeEditing="True" />

<WeekView DayStartTime="07:00:00" WorkDayEndTime="18:00:00" WorkDayStartTime="07:00:00" />

<Localization AdvancedAllDayEvent="Todo el d&#237;a" AllDay="Todo el d&#237;a" AdvancedEditAppointment="Modificar Reserva"

AdvancedNewAppointment="Nueva Reserva" Cancel="Cancelar" ConfirmDeleteText="Esta seguro de querer eliminar la reserva?"

Save="Guardar" />

<DayView DayStartTime="07:00:00" WorkDayEndTime="18:00:00" WorkDayStartTime="07:00:00" />

</telerik:RadScheduler>

the error that throws me is:
Sys.webforms.PageRequestManagerParseErrorException: the message received the server could not be parsed. Common couses for this error are when the response is modified by call to Response.Write(), response filters HttpModules or server trace is enabled.
Details: error pasing near 'BEGIN:VCALENDAR VER'

that may be, thanks for your help