Проблемы с выгрузкой экселевского файла

 MemoryStream memoryStream = new MemoryStream();
 wb.SaveAs(memoryStream);

Response.Clear();
Response.ContentType = "application/vnd.ms-excel";
Response.AddHeader("content-disposition", "attachment;    filename=111.xlsx");
memoryStream.WriteTo(Response.OutputStream);
 Response.Flush();

wb.SaveAs(@"c:\\1\ddd.xlsx");
System.IO.File.WriteAllBytes(@"C:\\1\\filename.xlsx", memoryStream.ToArray());

protected void Respon_file(string name_f, XLWorkbook wb)
    {
 
MemoryStream memoryStream = new MemoryStream();
        wb.SaveAs(memoryStream);
memoryStream.Position = 0;
 
Response.Clear();
        Response.ContentType = "application/vnd.ms-excel";
        Response.AddHeader("content-disposition", "attachment;    filename="+name_f);
        Response.BinaryWrite(memoryStream.ToArray());
    Response.End();
}

 //workbook.SaveAs(@"c:\\1\\qqq.xlsx");
 
 
            Respon_file(Path.GetFileName(xsltPath), workbook);

 workbook.SaveAs(@"c:\\1\\qqq.xlsx");
 
 
            Respon_file(Path.GetFileName(xsltPath), workbook);

Responce.Expires = 0

Response.Expires = 0;

String line;
try
{
    //Pass the file path and file name to the StreamReader constructor
    StreamReader sr = new StreamReader("C:\\Sample.txt");
    //Read the first line of text
    line = sr.ReadLine();
    //Continue to read until you reach end of file
    while (line != null)
    {
        //write the line to console window
        Console.WriteLine(line);
        //Read the next line
        line = sr.ReadLine();
    }
    //close the file
    sr.Close();
    Console.ReadLine();
}
catch(Exception e)
{
    Console.WriteLine("Exception: " + e.Message);
}
finally
{
    Console.WriteLine("Executing finally block.");
}

FileStream? fstream = null;
try
{
    fstream = new FileStream("note3.dat", FileMode.OpenOrCreate);
    // операции с fstream
}
catch(Exception ex)
{  }
finally
{
    fstream?.Close();
}

using System;
using System.IO;
using System.IO.MemoryMappedFiles;
using System.Runtime.InteropServices;
 
class Program
{
    static void Main(string[] args)
    {
        long offset = 0x10000000; // 256 megabytes
        long length = 0x20000000; // 512 megabytes
 
        // Create the memory-mapped file.
        using (var mmf = MemoryMappedFile.CreateFromFile(@"c:\ExtremelyLargeImage.data", FileMode.Open,"ImgA"))
        {
            // Create a random access view, from the 256th megabyte (the offset)
            // to the 768th megabyte (the offset plus length).
            using (var accessor = mmf.CreateViewAccessor(offset, length))
            {
                int colorSize = Marshal.SizeOf(typeof(MyColor));
                MyColor color;
 
                // Make changes to the view.
                for (long i = 0; i < length; i += colorSize)
                {
                    accessor.Read(i, out color);
                    color.Brighten(10);
                    accessor.Write(i, ref color);
                }
            }
        }
    }
}
 
public struct MyColor
{
    public short Red;
    public short Green;
    public short Blue;
    public short Alpha;
 
    // Make the view brighter.
    public void Brighten(short value)
    {
        Red = (short)Math.Min(short.MaxValue, (int)Red + value);
        Green = (short)Math.Min(short.MaxValue, (int)Green + value);
        Blue = (short)Math.Min(short.MaxValue, (int)Blue + value);
        Alpha = (short)Math.Min(short.MaxValue, (int)Alpha + value);
    }
}

            return File(
                content,
                "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
                "Report.xlsx"
                );

public FileResult SaveEndOfBase()
        {
            var workbook = new XLWorkbook();
            var worksheet = workbook.Worksheets.Add("Лист1");
 
            //создадим заголовки у столбцов
            worksheet.Cell("A" + 1).Value = "Имя";
            worksheet.Cell("B" + 1).Value = "Фамиля";
            worksheet.Cell("C" + 1).Value = "Возраст";
 
            // 
 
            worksheet.Cell("A" + 2).Value = "Иван";
            worksheet.Cell("B" + 2).Value = "Иванов";
            worksheet.Cell("C" + 2).Value = 18;
            //пример изменения стиля ячейки
            worksheet.Cell("B" + 2).Style.Fill.BackgroundColor = XLColor.Red;
 
            // пример создания сетки в диапазоне
            var rngTable = worksheet.Range("A1:G" + 10);
            rngTable.Style.Border.RightBorder = XLBorderStyleValues.Thin;
            rngTable.Style.Border.BottomBorder = XLBorderStyleValues.Thin;
 
            worksheet.Columns().AdjustToContents(); //ширина столбца по содержимому
 
            // [B]вернем пользователю файл без сохранения его на сервере  ----!!!!!!!!!!!!!!!!!!!!![/B]
            using (MemoryStream stream = new MemoryStream())
            {
                workbook.SaveAs(stream);
                return File(stream.ToArray(), "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", "Base.xlsx");
            }
        }