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From Microsoft: https://support.office.com/en-us/article/Microsoft-Office-support-for-macOS-10-14-Mojave-3593253c-95dc-4522-a8f7-8fb4fd16aff3
Summary:
Microsoft Office support for macOS 10.14 Mojave
Excel for Office 365 for Mac Word for Office 365 for Mac More...
Word, Excel, PowerPoint, Outlook, OneDrive, Skype for Business, and OneNote will install and run on macOS 10.14 Mojave. Microsoft fully supports Office 2016, Office 2019 and Office 365 for Mac on 10.14 Mojave when you have the following Office updates installed:
- Office 365/2019 - Build 16.17.0 or later
- Office 2016 - Build 16.16.2 or later
- Skype for Business 16.21.65 or later
For the best experience with 10.14 Mojave, be sure to keep your Office apps up-to-date. If the version of Office installed on your Mac is earlier than 16.14, and you are not being offered updates, you can download the latest Office for Mac suite installer. See "What version of Office am I using?" if you don't know what version you're on.