Collaborate for free with online versions of Microsoft Word, PowerPoint, Excel, and OneNote. Save documents, spreadsheets, and presentations online, in OneDrive. Office 365 for Mac cannot be installed on macOS 10.12. Suggestions 1. Update macOS to the three most recent versions (High Sierra, Mojave, Catalina). D ownload and install the 16.29 build of Office for Mac, then set AutoUpdate to manual..