Bug: The file format and extension of sample.xls dont match. The file could be corrupted or unsafe. Unless you trust your source, don't open it.

[john1jan]

Current behavior

Getting this error after generating the file with xlswriter in windows. The file format and extension of sample.xls dont match. The file could be corrupted or unsafe. Unless you trust your source, don't open it.

Expected behavior

No error

Sample code to reproduce

import xlsxwriter

workbook = xlsxwriter.Workbook('hello.xlsx')
worksheet = workbook.add_worksheet()

worksheet.write('A1', 'Hello world')

workbook.close()

Environment

- XlsxWriter version:
- Python version:
- Excel version:
- OS:

Any other information

No response

OpenOffice and LibreOffice users

• [ ] I have tested the output file with Excel.

[jmcnamara]

That is just a standard error/warning that Excel gives when the file extension (xls in this case)doesn't match the file format (xlsx).

The same thing happens if you rename an Excel file from xlsx to xls so it isn't an XlsxWriter issue.