An optional update left Office unlicensed, and on a few PCs it took Office away

On 24 September an IT company in Belgium had five unrelated customers get in touch within about ten minutes, all saying the same thing. Word and Excel had started calling themselves an Unlicensed Product. Dozens of machines were affected, and every one of them was running Office 2016 or Office 2019 Home and Business, the kind you buy once and own.

The cause was KB5002907, released a day earlier under the title "Optional update for out-of-date Microsoft 365 Apps installations". Its job was to get Microsoft 365 installs that had fallen more than 90 days behind updating again. It was not supposed to go anywhere near perpetual Office, and despite the word optional, plenty of people say it arrived on its own through Windows Update. Affected PCs show a yellow banner giving five days before the apps stop working properly. In a smaller number of cases Office was removed outright, with one person reporting that all that survived was a Simplified Chinese language pack.

Microsoft has paused the rollout and says it is investigating. If your copy has gone unlicensed, re-entering the original product key or signing in with the Microsoft account the licence sits under brings it back. If Office vanished, you download and reinstall the version you paid for. Both of those depend on being able to find proof of purchase, so this is a good week to dig the key out of wherever it has been sitting since 2016.

Your documents are not involved in any of this, which is worth saying plainly because the first reaction to Word disappearing is usually to assume the worst. Files and the program that opens them are separate things. Still, a recent copy of them turns a bad update into an annoyance rather than a bad weekend, and Tendvane's one-click backup of Documents, Pictures and Desktop takes care of that part.