If you receive this message while trying to open .eml files within Windows 10 and Office 2016 Home and Business or even Office 365, this is due to Microsoft defaulting to installing 64-bit versions of Office.
The Windows preview host requires a 32-bit application previewer, according to this Microsoft article.
Typical archaic software constraints. It is what it is. Uninstall and reinstall the 32-bit version of Office.