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

Question

I have a button

<asp:LinkButton runat="server" ID="botonPfd" OnClick="BotonPdf_Click">
<i class="fa fa-file-pdf-o" style='color:#007bff;font-size:20px;cursor:pointer;' title="Generar pdf"></i>
</asp:LinkButton>

I click on a button, and run a method that generates a pdf'

public string gererar(Trabajo trabajo)
{
string plantilla = obtenerPlanilla();
plantilla = rellenarDetallesTrabajo(plantilla, trabajo);

        StringBuilder tablas = new StringBuilder();  
        List<Anotacion> anotaciones = trabajo.getAnotaciones();  
        for (int i = 1; i <= 7; ++i)  
        {  
            List<Anotacion> anotacionesTipo = (from a in anotaciones  
                                               where a.IdTipoAnotacion == i  
                                               select a).ToList();  
            if (anotacionesTipo.Count > 0)  
            {  
                string tabla = obtenerTabla().Replace("#TipoAnotacion#", ((ETiposAnotacion)i).ToString());  
                StringBuilder filas = new StringBuilder();  

                foreach (var anotacion in anotacionesTipo)  
                {  
                    filas.Append(obtenerFila().Replace("#Fecha#", anotacion.FechaAltaString)  
                                              .Replace("#NombreRecurso#", anotacion.Recurso.Nombre)  
                                              .Replace("#Contenido#", anotacion.Contenido));  
                }  
                tabla = tabla.Replace("#Filas#", filas.ToString());  
                tablas.Append(tabla);  
            }  
        }  

        plantilla = plantilla.Replace("#Tablas#", tablas.ToString());  

        var htmlToPdf = new NReco.PdfGenerator.HtmlToPdfConverter();  
        var pdfBytes = htmlToPdf.GeneratePdf(plantilla);  

        var filename = "C:/Users/RFPORTAG-local/Desktop/ed.pdf";  

        File.WriteAllBytes(filename, pdfBytes);  

        if (!string.IsNullOrEmpty(filename))  
        {  
            return filename;  
        }  

        return null;  
    }  

I can see that the pdf was generated in my desktop, but I am triyng to download it

Dim GenerarPdf = New GenerarPdfAnotaciones

        Dim url = GenerarPdf.gererar(id)  

        Dim client = New WebClient()  
        Dim buffer = client.DownloadData(url)  
        Response.ContentType = "application/pdf"  
        Response.AddHeader("content-length", buffer.Length.ToString())  
        Response.BinaryWrite(buffer)  

Answer 1

Hi @Eduardo Gomez ,
While asking a question you need to provide a minimal reproducible example.

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

This error can be caused if you put the button in the Updatepanel.
You can keep the button outside the update panel. If you don't want to move it, just add a trigger for the button on the update panel, the postback trigger.

<Triggers>  
<asp:PostBackTrigger ControlID="botonPfd" />  
</Triggers  

Or add code under the backend LinkButton:

Dim scriptManager As ScriptManager = scriptManager.GetCurrent(Me.Page)  
scriptManager.RegisterPostBackControl(Me.YourButtonNameHere)  

Best regards,
Lan Huang

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