MC1392559 – M365 Change Digest

One-line summary

Teams on macOS users may face screen sharing issues on older systems; in-product guidance and prompts to update macOS begin rolling out late July to help mitigate disruptions.

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Details

Summary

Microsoft Teams on macOS (versions earlier than Tahoe 26.4) has a known screen sharing issue causing blank screens, interruptions, or failures. In-product guidance will roll out by mid-August 2026. Users should update macOS to 26.4 or later or enable "Use Mac OS native sharing" in Teams settings.

Body (from Message Center)

Updated July 10, 2026: We have updated the timeline. Thank you for your patience.

[What and Why:]

We are informing you of a known issue affecting screen sharing reliability in Microsoft Teams on macOS under certain system conditions and on older macOS versions (earlier than macOS Tahoe 26.4). Users may experience scenarios such as blank or black screen sharing, unexpected interruptions, or failures to start sharing sessions. To help users recover more quickly and reduce meeting disruption, Teams will begin surfacing in-product guidance when a failure is detected and direct users to relevant documentation and recommended remediation steps, including updating macOS where applicable.

[Rollout Schedule:]

Update to the latest macOS version now.
We will begin rolling out in-product guidance for screen sharing failures in late July 2026 (previously late June) and expect to complete by mid-August 2026 (previously mid-July)

[Impact on Your Organization:]

Who is affected:

Users in GCC, GCC High, and DoD environments who use Microsoft Teams on macOS
Users on older macOS versions (earlier than macOS Tahoe 26.4)
Users whose devices are experiencing system constraints, such as low memory or disk pressure
IT admins and helpdesk teams that support macOS device update policies and Teams troubleshooting

Platforms/Services:

Platform: macOS
Service: Microsoft Teams
Cloud instances: GCC, GCC High, DoD

What will happen:

Users may encounter screen sharing issues such as:

Blank or black screens during sharing.
Unexpected interruptions during sharing sessions.
Failure to start screen sharing.

When a failure is detected:

Users will see an in-product message prompting them to retry sharing.
Where applicable, users will be prompted to update their macOS version.

Updated documentation will outline common causes and remediation steps.
Updating to macOS Tahoe 26.4 or later resolves the issue.
As a mitigation, users can enable:

Teams Settings > General > Screen sharing > Use Mac OS native sharing.
No restart is required after changing this setting.

This guidance experience is enabled by default; no admin configuration is required.

[Action Required/Recommendations:]

Action is recommended:

Identify users running macOS versions earlier than macOS Tahoe 26.4.
Communicate this known issue and expected symptoms to users.
Recommend updating affected devices to macOS Tahoe 26.4 or later where possible.
Review device management policies to ensure updates can be applied.
Update internal helpdesk documentation to include:
- Symptoms of screen sharing failures.
- macOS update as the primary resolution.
- Alternative mitigation using Mac OS native sharing.
Prepare support teams to assist users who require elevated privileges to update macOS.

Suggested helpdesk message: If screen sharing in Teams on macOS shows a blank screen, stops unexpectedly, or fails to start, retry sharing and ensure the device is updated to macOS Tahoe 26.4 or later. You can also enable "Use Mac OS native sharing" in Teams under Settings > General > Screen sharing.

[Compliance considerations:]

No compliance considerations identified, review as appropriate for your organization.

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{
  "snapshot_item": {
    "action_required_by": null,
    "ai_action_required_by": "2026-06-30T00:00:00Z",
    "ai_actions": [
      "Identify users on macOS before Tahoe 26.4",
      "Communicate issue and update recommendation to users",
      "Recommend and enable updates to macOS Tahoe 26.4+",
      "Review update policies for affected devices",
      "Update helpdesk documentation",
      "Prepare support for user update issues"
    ],
    "ai_master_tags": [
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      "Admin"
    ],
    "ai_model": "gpt-4.1",
    "ai_summary": "Teams on macOS users may face screen sharing issues on older systems; in-product guidance and prompts to update macOS begin rolling out late July to help mitigate disruptions.",
    "ai_topics": [
      "Teams"
    ],
    "category": "planForChange",
    "details_map": {
      "Summary": "Microsoft Teams on macOS (versions earlier than Tahoe 26.4) has a known screen sharing issue causing blank screens, interruptions, or failures. In-product guidance will roll out by mid-August 2026. Users should update macOS to 26.4 or later or enable \"Use Mac OS native sharing\" in Teams settings."
    },
    "id": "MC1392559",
    "importance": 4,
    "is_major_change": false,
    "last_modified": "2026-07-10T16:30:26Z",
    "ms_products": [
      "Teams"
    ],
    "platforms": null,
    "roadmap_ids": [],
    "services": [
      "Microsoft Teams"
    ],
    "severity": "normal",
    "tags": [
      "Updated message",
      "User impact",
      "Admin impact"
    ],
    "title": "(Updated) Microsoft Teams: Known issue affecting screen sharing on macOS"
  }
}