KB5002907 is an optional Microsoft 365 update targeting installations more than 90 days out of date. Despite being optional, it reportedly installed automatically on some systems, affecting perpetual Office 2016 and Office 2019 licenses by causing deactivation or removal of the Office suite. Issues include Office showing as an unlicensed product and, in rare cases, complete removal of Office installations. Reactivation or reinstallation is required to restore functionality. Microsoft paused the update rollout and is investigating the issue, noting possible complications with mixed 32-bit and 64-bit Office components, though this is unconfirmed.

The update caused legitimate perpetual Office 2016 and Office 2019 licenses to become deactivated or, in rare cases, led to complete removal of Office installations. This disruption affects user productivity by requiring manual reactivation or reinstallation of Office. No evidence of security compromise or exploitation is reported.

Microsoft has paused the rollout of KB5002907 and is investigating the issue. Users affected by license deactivation should attempt to reactivate their Office products using their original product keys or by signing into their Microsoft accounts to select the license. In cases where Office was removed, users should reinstall their purchased Office 2016 or Office 2019 copies. No further action is recommended until Microsoft provides updated guidance.