Microsoft has confirmed a known issue in Teams on macOS that causes screen sharing to fail, freeze, or show a blank black screen during meetings.
The bug affects users running macOS versions older than macOS Tahoe 26.4, and Microsoft has now updated its rollout timeline for a fix, according to Message Center update MC1392559.
Users on affected devices may see their shared screen appear blank or black to other participants, experience sharing sessions that stop unexpectedly mid-meeting, or find that sharing fails to start altogether.
Microsoft notes the issue tends to show up more often on devices facing system constraints, such as low memory or high disk usage, in addition to outdated macOS versions.
Microsoft Teams on macOS
This issue mainly impacts organizations using Microsoft 365 Government cloud environments, specifically GCC, GCC High, and DoD tenants, running Teams on macOS.
Any user on a Mac still running a version earlier than macOS Tahoe 26.4 is at risk, and IT admins and helpdesk teams supporting these environments will need to prepare for related support tickets.
Microsoft originally planned to roll out in-product guidance by late June, but that timeline has since shifted. In-product guidance is now expected to begin rolling out in late July 2026, with full rollout completion targeted for mid-August 2026.
Once live, Teams will automatically detect a sharing failure and show users an in-product prompt to retry sharing, along with a suggestion to update macOS if that’s the likely cause. This experience will be enabled by default, so admins won’t need to configure anything.
You don’t have to wait for the automatic guidance to resolve this. Updating macOS to Tahoe 26.4 or later fully resolves the issue. Alternatively, enabling “Use Mac OS native sharing” in Teams under Settings > General > Screen sharing offers a quick workaround that doesn’t require a restart.
Microsoft recommends organizations identify users still running macOS versions earlier than Tahoe 26.4 and communicate the issue and expected symptoms to them ahead of time.
Admins should push macOS updates where device management policies allow, and update helpdesk documentation to cover the symptoms, the macOS update fix, and the native sharing workaround. Support staff should also be prepared to assist users who need elevated privileges to update their systems.
Microsoft has flagged no compliance concerns tied to this issue, though organizations should review it against their own internal policies as needed.
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