I need to create a new XSLM spreadsheet document.
I am using this code. The resulting file cannot be opened by Excel 2010 and it is actually an XLSX file. I am able to open when I change its extension to XLSX.
```
var workbook = new XLWorkbook();
var worksheet = workbook.Worksheets.Add("Sample Sheet");
worksheet.Cell("A1").Value = "Hello World!";
workbook.SaveAs("HelloWorld.xlsm");
```
I am using this code. The resulting file cannot be opened by Excel 2010 and it is actually an XLSX file. I am able to open when I change its extension to XLSX.
```
var workbook = new XLWorkbook();
var worksheet = workbook.Worksheets.Add("Sample Sheet");
worksheet.Cell("A1").Value = "Hello World!";
workbook.SaveAs("HelloWorld.xlsm");
```