Activation error in Office 365 / Office 16
Ref: https://support.office.com/en-ie/article/unlicensed-product-and-activation-errors-in-office-0d23d3c0-c19c-4b2f-9845-5344fedc4380
If Office activation fails, you'll see Unlicensed Product or Non-commercial use / Unlicensed Product
in the title bar of your Office apps, and most features of Office are
disabled. To restore all features of Office, you'll need to fix the
problem that's causing activation to fail.
Use the Activation Troubleshooter for Office 365 and Office 2016
This troubleshooter runs on Windows PCs and can fix activation errors
for Office 365, Office 2016, and individual Office 2016 apps, like
Visio, Project, Word, and Outlook.
1- Click HERE to download the troubleshooter
2- Run the tool and then follow the on-screen instructions