1] Unblock the Word file Maybe the file is blocked, which is why Word cannot open the file; this usually occurs when you receive a file from Outlook or a similar email client.

Hello, I encountered the same problem (node.js v16, html-to-docx v1.8.0). For me this seems to occur only in desktop MS Word, but in WordPad, google docs and MS Word online (Microsoft 365) everything ...