You might see the “Subscription expired” message in a yellow warning bar across the top of an Office application after you’ve renewed Office 365.
Why it happens: Your Office 365 subscription expired, before you renewed.
How to turn it off: After renewing your subscription, close all your open office applications and open them again to use them. You may have to re-enter the Microsoft account associated with your subscription. If you do not want to worry about ending your Office 365 subscription in the future, consider turning on Auto Renewal.