Code doesn't work when deploying on Server - asp.net

Question

I have written the following code to export data to excel.
This code works fine on local,but when we deploy this code on Server (UAT),it doesn't work.
If we restart server, it works for a while but again after a while it fails.
Code:
public void ExportToExcelFunction(string FlName, DataTable mydt, string DispColName, string BindCols)
{
Excel.Application xlObj = new Excel.Application();
object oMissing = System.Reflection.Missing.Value;
xlObj.Visible = false;
//vinod
string filepath = Server.MapPath("Export");
string strFlName = filepath + "\\Master.xlsx";
Excel.Workbook xlWB = xlObj.Workbooks.Open(strFlName, 0, true, 5, "", "", false, Excel.XlPlatform.xlWindows, "", true, true, 0, true);
Excel.Worksheet xlSheet = (Excel.Worksheet)xlWB.ActiveSheet;
int cols = mydt.Columns.Count;
int rows = mydt.Rows.Count;
//Added for export to excel
try
{
//For Column
string[] strCols = DispColName.Split(',');
for (int i = 1; i <= strCols.Length; i++)
{
if (strCols[i - 1].Length > 0 && strCols[i - 1] != null)
xlSheet.Cells[1, i] = Convert.ToString(strCols[i - 1]);
}
// for Row
string[] strColBind = BindCols.Split(',');
for (int r = 0; r < rows; r++)
{
for (int c = 0; c < strColBind.Length; c++)
{
xlSheet.Cells[r + 2, c + 1] = mydt.Rows[r][strColBind[c]];
}
}
}
catch (Exception ex)
{
}
String newFlName = "\\" + DateTime.Now.Ticks.ToString() + "_" + FlName + ".xls";
xlWB.SaveAs(filepath + newFlName, Excel.XlFileFormat.xlWorkbookNormal, "", "", false, false, Excel.XlSaveAsAccessMode.xlExclusive, true, false, "", true);
xlWB.Close(true, oMissing, oMissing);
xlObj.Quit();
System.IO.FileInfo file = new System.IO.FileInfo(#"" + filepath + newFlName + "");
Response.Clear();
Response.ClearHeaders();
Response.ClearContent();
Response.AppendHeader("Content-Disposition", "attachment; filename = " + FlName + ".xls");
Response.AppendHeader("Content-Length", file.Length.ToString());
Response.ContentType = "application/download";
Response.WriteFile(file.FullName);
Response.Flush();
Response.Close();
Response.End();
}

Answer 1

Two things you should know.
The first, is that your code appears to be using Excel Interop Services, thus it requires Excel to be installed on the server.
The second thing is that using Excel Interop Services on the server side is not supported by Microsoft, for a number of good reasons.
Instead, I suggest using an alternative library such as EPPlus or Open Office XML SDK, both of which run on the server side just fine.