Exception Thread was being aborted

[MatGei]

I am using latest version 1.0.5 of ClosedXML.Extensions.AspNet

I have a static class ExcelService containging this code:

public static void CreateExcelSheetForDataTableAndAddToResponse(DataTable tableToHandle, HttpResponse response, string fileName)
{
DataSet ds = new DataSet("REPORTS");
ds.Tables.Add(tableToHandle);

        var wb = new XLWorkbook();

        wb.Worksheets.Add(ds);

        if (wb.Worksheets.FirstOrDefault() != null && wb.Worksheets.FirstOrDefault().Columns() != null)
        {
            wb.Worksheets.FirstOrDefault().Columns().AdjustToContents();
        }
        fileName = fileName.EndsWith(".xlsx") ? fileName : fileName + ".xlsx";
        //wb.DeliverToHttpResponse(response, fileName);
        response.DeliverWorkbook(wb, fileName, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
    }

I call it like this from my code behind for a asp.net page:

ExcelService.CreateExcelSheetForDataTableAndAddToResponse(myDataTable, this.Response, fileName.ToFileName());

My string extension for safe file name generation:

    public static string ToFileName(this string s)
    {
        
        string regexSearch = new string(Path.GetInvalidFileNameChars());
        Regex rs = new Regex(string.Format("[{0}]", Regex.Escape(regexSearch)));
        s = rs.Replace(s, "");

        return s.Replace(" ", "_");  // replace space with underscore
    }

The response stream gets the file with both delivery methods but both delivery methods also throws a Thread was being aborted exception. Catching this exception explicitly and it all works. But why is it throwing that Thread exception?