Renaming/deleting main sheet causes corrupt excel file

[kkellogg378]

Doing any of the following:

excel = Excel.createExcel();
excel.rename(excel.sheets.keys.first, sheetName);

excel = Excel.createExcel();
excel.rename("Sheet1", sheetName);

excel = Excel.createExcel();
excel[sheetName];
excel.setDefaultSheet(sheetName);
excel.delete('Sheet1');

followed by

Sheet sheetObject = excel[sheetName];
sheetObject.setDefaultColumnWidth(30.0);
sheetObject.setDefaultRowHeight(15.0);

var fileBytes = excel.save();
File(path)
  ..createSync(recursive: true)
  ..writeAsBytesSync(fileBytes!);

results in a corrupt excel file on excel 4.0.6