Microsoft will upgrade the backend service for Captions & Subtitles in PowerPoint by September 2026. Users with versions older than 16.0.19426.20218 (Windows) or 16.103.1207.4 (macOS) will lose access. Organizations should update PowerPoint to maintain this feature without changing settings.
Applies to: Microsoft 365 apps
Source: mc.merill.net — data via Merill Fernando's open archive (MIT).