Desktop download not Working

Actually, the Guides are completely up to date for the desktop edition. See these:

https://www.manager.io/guides/how-to/add-a-new-business-desktop-edition
https://www.manager.io/guides/best-practices/data-backup-restoration-and-transfer

You might also read the release note for version 17.4.0, although several improvements have already been made since it was published: