Microsoft paused an Office update after it deactivated, and in some cases removed, Office 2016 and 2019

Microsoft has paused the rollout of KB5002907, an optional Microsoft 365 Apps update offered through Windows Update, after reports that it deactivated or removed bought-outright copies of Office 2016 and Office 2019. Its support page for the update now opens with a notice: "Microsoft has received reports of unexpected results on some devices running Office 2016 or Office 2019 after this update is installed." It goes on: "As part of the repair action applied by this update, some devices were left without functioning versions of Microsoft 365 Apps or Office. To prevent additional devices from being affected, we have paused the rollout of this update."

What the update was for

KB5002907 was aimed at subscription installs that had stopped updating. Microsoft's page says it "is available only for Windows PCs with Microsoft 365 Apps installations that are more than 90 days out of date and use Current Channel or Monthly Enterprise Channel", that it is offered as an optional update rather than a Windows update, and that it "does not install automatically". It lists Windows 10 22H2, Windows 11 23H2 through 26H1 and Windows Server 2019 to 2025 as the platforms it applies to. Where Microsoft 365 Apps updates are managed through Group Policy or Cloud Update, the page says the update makes no changes, which is why managed tenants have been quiet about it.

What went wrong

BleepingComputer reported on 26 September that Christian Van Hautte, who runs a managed service provider in Belgium, had five unrelated customers contact his company within about ten minutes on 24 September, with dozens of PCs affected. All of them were running Office 2016 or Office 2019 Home & Business, the one-off purchase versions rather than subscriptions, and all showed Office as an "Unlicensed Product". Re-entering the original product key restored activation. He also told BleepingComputer that, despite being listed as optional, the update installed on his customers' machines without anyone choosing it, and that it appears to remove and reinstall the existing Office installation as part of its process. Where a 32-bit Office sat alongside a 64-bit component such as the Access Runtime, he found the reinstall can fail, because Office setup refuses to mix architectures, leaving the machine with no Office at all. Microsoft has not confirmed that explanation. Its statement to BleepingComputer was: "We are aware of these reports and have paused the update while we investigate. Additional customer guidance will be communicated via appropriate channels."

If a machine has been hit

Microsoft's page gives two resolutions. If Office shows as unlicensed, reactivate the purchased product. In what it calls rare cases where Office has been removed, download and reinstall Office 2016 or 2019. BleepingComputer's report adds that some users found retyping the key was not enough and had to sign in with the Microsoft account the licence is tied to and select it there. That is the catch for a small business. A 2016 licence may be registered to an email address nobody has used for years, and the product key may be on a sticker in a drawer or nowhere at all. There is a bigger point underneath. Microsoft's own lifecycle list has Office 2016 and Office 2019 leaving support on 14 October 2025, so those installs have had no security fixes for nearly a year. An update that knocks them over is a nuisance. The state they were already in is the risk.