Opening the attached xlsx file generates a NullReferenceException in ExcelRangeBase constructor. The problem comes down to ExcelWorkbook.GetDefinedNames() line 171 has this code:
namedRange = _names.Add(elem.GetAttribute("name"), new ExcelRangeBase(Worksheets[addr._ws], fullAddress));
however, WOrksheets[addr._ws] returns null which later leads to ExcelRangeBase. At the time it's iterating over the defined name "RaceName" which has an InnerText of "#Ref!" and is not a valid worksheet.
I'm not sure why the xlsx has "#Ref!" inside it. Viewing it in Excel 2010 works fine without any errors visible anywhere.
Even if there was a formula error somewhere causing "#Ref!" somewhere, it shouldn't fail to open and certainly shouldn't throw a generic NullReferenceException.
My calling code to generate the exception is this:
using (var xp = new ExcelPackage(new FileInfo(path)))
if (xp.Workbook.Worksheets.Count == 0)
the exception is thrown when I try to access Workbook property.