When renewing your Microsoft Office license or switching to a new device, the licenses can malfunction and stop letting you edit or save files. This is a common issue for Macs, where upon opening a file in a Microsoft application, the following message will be displayed:

This occurs when your current license has expired or upon renewing the license and it failing to sync. To fix this, you will need to remove the old Office license files. You can follow the steps provided by Microsoft on their support page (How to Remove Office Files on a Mac). After uninstalling the licenses, try opening one of the MS apps. Microsoft Office or the individual application should prompt you to log in upon opening the app. This should activate your current license.