Cannot open xlsx files created by XLSL.writeFile

I’m trying to use js-xlsx to generate xlsl files for my Electron app. I followed the demo and can also create a xlsl file, here is the code:

const data = [
    ["Name", "Age", "Location"],
    ["Bob", 24, "NYC"],
    ["Jason", 30, "LA"]
];
const ws: XLSX.WorkSheet = XLSX.utils.aoa_to_sheet(data);
const wb: XLSX.WorkBook = XLSX.utils.book_new();
XLSX.utils.book_append_sheet(wb, ws, "Sheet1");
XLSX.writeFile(wb, "SheetJS.xlsx");

Everything works fine before opening the generated file with Excel, when Excel warned me that the file cannot be opened, because of invalid file format or extesion. I’m not sure what’s wrong about my code, did I miss something?

Here’s how my development env goes:

• OS: Window 10
• Electron: 5.0.1
• Angular: 7.2.15
• xlsx: 0.15.0
• Excel: Microsoft Office Professional Plus 2013

[voxsoftware]

I solved the problem with this XLSX.writeFile (wb," SheetJS.xls ");

When you write the file, the last line of your code, you must change XLSX.writeFile (wb," SheetJS.xlsx "); To XLSX.writeFile (wb, 'book.xls') In other words, change the format of the xlsx file to xls

This is not useful. Why use old format xls?

[mateombar]

I solved the problem with this XLSX.writeFile (wb," SheetJS.xls ");

When you write the file, the last line of your code, you must change XLSX.writeFile (wb," SheetJS.xlsx "); To XLSX.writeFile (wb, 'book.xls') In other words, change the format of the xlsx file to xls