"We are aware of these reports and have paused the update while we investigate. Additional customer guidance will be communicated via appropriate channels," a Microsoft spokesperson told BleepingComputer.
KB5002907: the update and its stated purpose
KB5002907 — titled "Optional update for out-of-date Microsoft 365 Apps installations" — was published to help bring Microsoft 365 Apps installations that are more than 90 days out of date back to a current build for their assigned update channel. The KB release notes state: "This optional update is available only for Windows PCs with Microsoft 365 Apps installations that are more than 90 days out of date and use Current Channel or Monthly Enterprise Channel," and add that "Installing the update can help the apps resume updating and move to a current build for the device's assigned update channel." Microsoft also said the update is offered through Windows Update and does not install automatically.
Reports from MSPs and users in late September
Within hours of KB5002907's roll-out around September 23, multiple administrators and end users reported unexpected license and installation problems. Christian Van Hautte, who runs a managed service provider (MSP) in Belgium, told BleepingComputer that five unrelated customers contacted his company within approximately ten minutes on September 24, with dozens of PCs affected across those organizations.
Van Hautte said the affected installations were all Office 2016 and Office 2019 Home & Business perpetual (one-time purchase) licenses. In many cases, affected installs showed as an "Unlicensed Product"; re-entering the original Office product key restored activation on those systems. Van Hautte also warned that although KB5002907 is listed as optional, it installed automatically on his customers' devices.
This site is the portfolio.
OSINTSights runs on Cloudflare Workers, D1, R2, and Vectorize, with an AI pipeline on Hetzner ARM. Nubivance designed, built, and operates it. We do the same for clients.
See what we buildObserved failure modes: deactivation, failed migration, and removal
Van Hautte reported that KB5002907 appears to remove and then reinstall — or migrate — the existing Office installation as part of its update process. He said that on systems where Office components used different architectures (for example, a 32‑bit Office 2016 or 2019 installation alongside a 64‑bit Microsoft Access Runtime), the reinstall can fail because "Microsoft Office setup does not allow mixing 32‑bit and 64‑bit Office products." In those cases, he said the existing Office suite is removed but not successfully reinstalled, leaving the device without Office.
Other reports surfaced online at approximately the same time. One Reddit poster said multiple Office 2019 installations became deactivated and that entering product keys again restored activation on at least some devices; the poster later updated the thread to say the problem was not limited to Office 2019 and that some systems required signing into a Microsoft account and selecting the license rather than just entering the key. In the Microsoft forums and elsewhere, users and administrators posted similar accounts, including one comment that "My Office 2019 and dad's Office 2016 installs both got nuked overnight... both are 100% legit keys purchased long ago." Some administrators also reported complete uninstalls.
Microsoft has not confirmed Van Hautte's assertion that mixed‑bitness installations cause the reinstall failures.
Microsoft pauses rollout and updates guidance
After BleepingComputer contacted Microsoft about the reports, the company confirmed it had paused the rollout while investigating. Microsoft updated the KB5002907 support bulletin to acknowledge "reports of unexpected results on some devices running Office 2016 or Office 2019 after this update is installed," and added: "To prevent additional devices from being affected, we have paused the rollout of this update."
Microsoft confirmed two different outcomes for affected installations. In some cases Office may appear unlicensed; Microsoft recommends customers reactivate their purchased product. In what the company calls "rare cases," Office may be removed entirely; Microsoft instructs those users to download and reinstall their purchased copy of Office 2016 or Office 2019.
What this means for MSPs, enterprises, and end users
- MSPs: Several MSPs reported multiple client incidents within minutes, and one said the update installed automatically despite being optional. MSPs will likely need to check client fleets for unlicensed Office installs, be prepared to advise on reentering product keys or account‑based license selection, and handle any required reinstalls.
- Enterprises and IT teams: The update targets machines with outdated Microsoft 365 Apps but affected included perpetual Office 2016 and 2019 installations; teams should note Microsoft's pause and follow its guidance before redeploying KB5002907, and inventory mixed 32‑bit/64‑bit Office components that could complicate a reinstall.
- End users: Some users reported successful reactivation by reentering product keys, while others were required to sign into a Microsoft account and select the license. In "rare cases" where Office was removed, Microsoft directs users to download and reinstall their purchased copy of Office 2016 or Office 2019.
Microsoft has paused KB5002907 and is investigating the reports; it will communicate further guidance "via appropriate channels," the company said. Until then, affected users can follow Microsoft's immediate advice to attempt reactivation or, if removal occurred, to reinstall their purchased Office copies — and administrators should treat the paused rollout as a prompt to audit affected devices and prepare recovery steps.
Source: BleepingComputer — Microsoft pauses KB5002907 update after Office license deactivations
