Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
This behavior matches an Office activation problem. When Word is not activated, features can be disabled and Word may open in a limited mode where documents can be viewed but not properly edited or saved.
Try this in order:
- In Word, select Sign in and use the Microsoft account that has the Microsoft 365 subscription or Office purchase.
- If Word shows Product deactivated, signing in with the licensed account activates Office.
- If Office came preinstalled on the device, check whether it was only a trial.
- If the trial expired, full desktop use requires starting a Microsoft 365 Family trial or buying Office.
- If purchase is not wanted, select Use free at Office.com to use Word on the web.
- If the account is already signed in but Word still shows deactivated, the install may have been signed out or deactivated on this device.
- Sign in again in Word.
- If the sign-in or install limit has been reached, sign out of or deactivate another Office install.
- Update Office.
- Open any Office app.
- Go to File > Account.
- Under Product Information, choose Update Options > Update Now.
- If Update Now is not shown, select Enable Updates first.
- Avoid creating new documents until activation is restored.
- In reduced or deactivated mode, Word may not allow normal create, edit, or save behavior, which explains why content appears to vanish after closing an unsaved document.
If the goal is to keep using the desktop app, activation is the required fix.