C# ExcelDataReader.Exceptions.HeaderException: 'Invalid file signature.'

Question

I am trying to read my excel file using the windows application that I am currently developing now.
It consist of 8 headers and contains of almost 300 data value.

If you know the solution please help me ;(

And additional question, what nuget can I use to manipulate each header to expand on its own, so that the data can be readable.

My Copy of Code:

private void btnBrowse_Click(object sender, EventArgs e)
{
    using (OpenFileDialog openFileDialog = new OpenFileDialog() { Filter = "MS Excel 2007 onwards |*xls" })
    {

        if (openFileDialog.ShowDialog() == DialogResult.OK)
        {
            txtFilename.Text = openFileDialog.FileName;
            using (var stream = File.Open(openFileDialog.FileName, FileMode.Open, FileAccess.Read))
            {
                using (IExcelDataReader reader= ExcelReaderFactory.CreateReader(stream))           
                {
                    DataSet result = reader.AsDataSet(new ExcelDataSetConfiguration()
                    {
                        ConfigureDataTable = (_) => new ExcelDataTableConfiguration() { UseHeaderRow = true }
                    });
                    tableCollection = result.Tables;
                    cboSheet.Items.Clear();
                    foreach (DataTable table in tableCollection)
                    cboSheet.Items.Add(table.TableName); //add sheet to combobox
                }
            }
        }