Why this happens
This behavior is usually caused by one of the following:
Activation hasn’t fully completed yet or is still syncing
A corrupted Office identity/profile cache
Remnants from a previous Office installation
Updates or compatibility conflicts affecting startup
Step-by-step fix
Restart your PC
Restart first. If Office was just installed or recently reactivated, a reboot often finalizes background setup steps.
Check activation status (if you can)
Open an Office app and go to File > Account. Look under Product Information.
If it shows Office is not activated, re-enter your product key or confirm you’re signed in with the correct Microsoft account used for redemption. If you can’t keep an app open long enough, continue with the next steps.
Run Office Repair
Go to Control Panel > Programs > Programs and Features.
Select Microsoft Office and click Change.
Run Quick Repair first. If the issue continues, run Online Repair. This repairs core files without deleting your documents.
Clear Office credentials and cache
A corrupted cache can cause Office to close immediately.
Press Windows + R, type the following, and press Enter:
control /name Microsoft.CredentialManager
In Credential Manager, remove entries related to Office (examples: MicrosoftOffice16 or similar Office entries).
Then open Windows + R again and paste:
%localappdata%\Microsoft\Office\16.0\Licensing
(Delete the files inside that folder.)
If your folder uses a different number, use the one matching your installed Office version.
Restart your PC and try opening Office again.
Fully remove and reinstall Office (if needed)
If the issue still persists, uninstall Office completely using the uninstall option included in your automatic Office installer (recommended), then reinstall using the installer link from your delivery instructions.