Downloads to Excel should work with Excel 2016 or later, but since software changes frequently, if you are having trouble, you may need to upgrade your Excel version. The export program doesn't check the version of Windows that the user is running.
The download feature targets Microsoft Excel, so it won't work with Open Office (or Microsoft Works, Corel, Lotus, or any other office productivity packages). Because the export is both exporting data to the program and building graphs, it uses commands that are embedded in the DLLs that are part of Excel. The DLLs won't exist on the PC if Excel isn't installed.