Excel application scope : Error opening workbook. Make sure Excel is installed. - Using OpenOffice

Hi, by right when downloading excel package, openoffice is supported. (Execute Excel related operations using the Open Office XML format (XLSX) or Excel.Interop) My filetype was xlsx which worked when I had my excel free trial. Now the trial is over. I am using Open Office instead but i tried changing the file to xml. But the error still exists