Microsoft has halted distribution of the KB5002907 update after receiving reports that the patch was deactivating—and in some instances entirely uninstalling—perpetual Office 2016 and Office 2019 deployments.
Designated as an "Optional update for out-of-date Microsoft 365 Apps installations," KB5002907 was designed to assist users whose Microsoft 365 Apps had not received updates for more than 90 days. According to the release notes, "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optional update is available only for Windows PCs with Microsoft 365 Apps installations that are more than 90 days out of date and use Current Channel or Monthly Enterprise Channel." The update was meant to "help the apps resume updating and move to a current build for the device's assigned update channel."
Although Microsoft characterized KB5002907 as optional and stated it would not deploy automatically through Windows Update, the patch began affecting perpetual Office installations shortly after its September 23 release.
Widespread activation issues reported
Christian Van Hautte, an MSP operator based in Belgium, reported that five separate customers contacted his firm within roughly ten minutes on September 24, each experiencing license problems across dozens of machines. "The affected installations are all Office 2016 and Office 2019 Home & Business (perpetual/one-time purchase licenses)," Van Hautte explained. "The common factor is KB5002907, an update released around September 23 and described as targeting 'outdated Microsoft 365 Apps installations' — but it is clearly also landing on perpetual (non-subscription) Office installs and breaking their license state."
Van Hautte noted that while the update was classified as optional, it installed automatically on his customers' systems. He discovered that KB5002907 removes and reinstalls—or migrates—the existing Office installation as part of its update sequence.
A particular problem emerged on systems running Office components with mismatched architectures. When a 32-bit Office 2016 or 2019 installation coexisted with a 64-bit Microsoft Access Runtime, the reinstall process would fail because Microsoft Office setup prohibits mixing 32-bit and 64-bit products. In these scenarios, the existing Office suite was removed but not successfully reinstalled, leaving machines without Office entirely. Microsoft has not confirmed whether mixed-bitness configurations trigger this behavior.
Re-entering the original Office product key restored activation on affected systems, according to Van Hautte. However, some users later reported needing to sign into a Microsoft account and select the license rather than simply entering the key.
Similar complaints surfaced across Reddit, Microsoft forums, and other online channels around the same timeframe. One Reddit user reported multiple Office 2019 installations becoming deactivated and said reentering product keys restored activation on at least some devices. Another administrator described customers whose Office had been completely removed. "My Office 2019 and dad's Office 2016 installs both got nuked overnight... both are 100% legit keys purchased long ago," one user commented.
Microsoft pauses rollout and acknowledges problems
After BleepingComputer contacted Microsoft regarding the reports, the company confirmed it had suspended the update pending investigation. "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 stated.
Microsoft updated the KB5002907 support bulletin to acknowledge the issues. "Microsoft is investigating reports of unexpected results on some devices running Office 2016 or Office 2019 after this update is installed," the company noted. "To prevent additional devices from being affected, we have paused the rollout of this update."
The company identified two distinct failure modes affecting Office installations. In some cases, Office appears unlicensed, and Microsoft recommends customers reactivate their purchased product. In what Microsoft describes as "rare cases," Office is removed entirely, requiring users to download and reinstall their purchased copy of Office 2016 or Office 2019.