Teams on macOS has a major bug for some users, and Microsoft is rolling out guidance

Teams is one of the most used online communication and collaboration tools especially in enterprise and school environments. It is available on a variety of platforms including Android, iOS, Windows, macOS, and the web. As such, it is a major problem when users on any of the aforementioned platforms get affected.

In its Message Center advisory MC1392559, Microsoft acknowledged a bug impacting Teams customers on certain versions of macOS a few weeks ago. Basically, if affected users start sharing their screen, they'll see a black or blank screen, experience interruptions while sharing, and even face complete failure in screen sharing functionality.

This is impacting customers using macOS versions older than Tahoe 26.4, and PCs which are resource-constrained on disk and memory. Interestingly, the scope of this issue appears to be limited as Microsoft has only listed Government Community Cloud (GCC), GCC High, and Department of Defense (DoD) as the affected platforms.

Since it can be confusing to customers when the bug appears randomly and troubleshooting methods aren't always obvious, Microsoft is working on introducing some in-product guidance that automatically gets shown to users when a screen sharing failure is detected. They'll be asked to retry sharing their screen and will also be requested to update their macOS version, when applicable. If that is not possible, the Redmond tech giant has urged users to apply a mitigation that involves navigating to Teams Settings > General > Screen sharing > Use Mac OS native sharing. A restart isn't required.

Regardless, Microsoft has recommended IT admins to inform their helpdesks about this issue, update their internal documentation, communicate the problem across the organization, and update macOS Tahoe 26.4 devices, where possible. The in-product guidance will begin rolling out later this month and should hopefully be available to all by mid-August.