Microsoft investigating 365 Office activation gremlin

It's not just you, there is indeed an activation problem in Microsoft 365 Office triggered by administrators making changes at the licensing level.

The problem has been ongoing for a few months and manifests as a notification warning some users that their Microsoft 365 license will soon be deactivated. It's all a bit alarming for the users affected and is undoubtedly cluttering up the help desk of affected enterprises.

Microsoft has confirmed that there is a problem but is unsure exactly what is causing it. The company believes it has something to do with licensing changes made by the administrator.

The Windows vendor gave five possible reasons for the issue. These were:

• Change in licensing group, where user is moved from one group to another (applies to both Azure AD Groups and security groups synced from on-premises AD)
• Changes in license/product assignment at the user level. Example: switching user license from Office 365 E3 subscription to Microsoft 365 E3 subscription
• Removing and re-adding users to the same license group or different license group
• Toggling license or service plan for the users
• If administrators have turned off the "Latest version of Desktop Apps" service plan under the Microsoft 365 subscription for users

Heaven forbid any Microsoft customer would want the latest version of the Office Desktop Apps at their fingertips.

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Fixing the issue is relatively straightforward – if there's a Reactivate button, a user can click that and then sign in again. Alternatively, the tried and tested approach of closing every Microsoft 365 app (including Outlook) and restarting them, followed by a sign-in, should do the trick.

If that still does not work, then it's time to start nagging your hardworking administrator.

As for the exact cause, Microsoft said: "Our engineering team is investigating the issue."

Admins have not had the easiest of times at the hands of Microsoft 365 over the last year. As well as the occasional outage, there have been problems with false malware alerts. In 2026, Microsoft will start switching Microsoft 365 Enterprise users to the new-look Outlook (with an option to switch back), which could cause a surge of help desk tickets for the unprepared. ®