Microsoft has paused the rollout of KB5002907, an optional update for out-of-date Microsoft 365 Apps installations, after reports that it deactivated or, in some cases, completely removed perpetual Microsoft Office 2016 and Office 2019 installations on Windows PCs.

The company confirmed the pause in an updated support bulletin and in a statement from a spokesperson, and says it is investigating the reports.

KB5002907 was released around September 23. According to Microsoft's release notes, the update targets only Windows PCs with Microsoft 365 Apps installations that are more than 90 days out of date and use Current Channel or Monthly Enterprise Channel. Microsoft describes it as optional, offered through Windows Update, and not installed automatically.

Problems surfaced on September 24. Christian Van Hautte, who runs a managed service provider in Belgium, says five unrelated customers contacted his company within roughly ten minutes, with dozens of PCs affected across those organizations.

Every affected installation was Office 2016 or Office 2019 Home & Business bought with a one-time purchase license, and the apps suddenly showed "Unlicensed Product." Van Hautte also says the update installed automatically on his customers' devices even though it is listed as optional.

Affected users describe in-app messages stating that normal functionality has been removed, plus yellow banners warning that five days remain before the apps stop working. One administrator needed multiple product reactivations, restarts, and account sign-ins before Office was stable again.

The update appears to remove and reinstall, or migrate, the existing Office installation. On systems that mix architectures, such as a 32-bit Office 2016 or 2019 suite alongside a 64-bit Microsoft Access Runtime, Van Hautte says the reinstall can fail because Office setup does not allow 32-bit and 64-bit products together.

In that case, the existing suite is removed but not reinstalled, leaving the PC without Office. Microsoft has not confirmed that mixed-bitness setups trigger this behavior.

"To prevent additional devices from being affected, we have paused the rollout of this update," Microsoft now states in the KB5002907 bulletin. The company lists two outcomes: Office showing as unlicensed, or, in what it calls "rare cases," Office being removed entirely.

Microsoft's guidance depends on which symptom a PC shows:

1. If Office reports that it is unlicensed, reactivate the purchased product. Re-entering the original Office product key restored activation for affected users.
2. If the key alone does not work, sign in with the Microsoft account tied to the purchase and select the license there, which some users needed to do.
3. If Office is gone from the PC, download and reinstall the purchased copy of Office 2016 or Office 2019.

Office 2016 and Office 2019 reached the end of support on October 14, 2025, and Microsoft said at the time that customers could keep using both suites. It is the second September problem for Office 2016 users, following an update that broke copy and paste in Excel 2016.

Microsoft has not said when KB5002907 will resume or whether a revised version will skip perpetual Office installations. The company says additional customer guidance will be communicated through its usual channels.