MS Teams updates in VDI are disabling Microphone Access

Jim Bennett 20 Reputation points
2026-08-13T14:51:08.9433333+00:00

We are a VMware Shop running VDI workstations. Teams is optimized via Omnissa/Slimcore.

When users got the updated Slimcore-capable optimization, for some reason, Microsoft is defaulting the Security & Privacy settings for the mic on the Client side to "Off." We created a user doc that worked well to resolve the issue.

But now, MS Teams updates are arriving daily and, in some cases, twice a day. Each time it updates, the client-side mic settings are being reset to "Off."

Is anyone else seeing this problem? I am trying to determine whether this is an issue with our environment or internal processes, or if this is coming from all of these random Teams updates.

Thank you for any information you might be able to offer.

Microsoft Teams | Microsoft Teams for business | Meetings and calls | Audio and video
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Answer accepted by question author
BabybooHN 2,450 Reputation points Independent Advisor
2026-08-13T15:11:13.8633333+00:00

Dear @Jim Bennett
I understand how frustrating it is when daily Microsoft Teams updates repeatedly reset client-side microphone permissions across your VMware/Omnissa VDI environment.

This is a known issue related to the new Teams VDI architecture (SlimCore) during rapid update cycles. New VDI Solution for Teams Architecture Provides an overview of the SlimCore media engine architecture, system requirements, and deployment principles across VDI environments.

With the new SlimCore optimization architecture, Microsoft Teams registers a local media plugin on the physical client endpoint (appearing under Windows App Privacy settings as Microsoft Teams VDI or Microsoft Teams VDI Optimizer).

Because Microsoft frequently pushes auto-updates to the Teams VDI client and SlimCore components, Windows treats each update as a modified or re-registered application binary. When Windows OS detects an app update without an enforced privacy policy, it defaults security permissions back to Off for safety.

Option 1: Enforce Client-Side Microphone Permissions via Group Policy
Instead of relying on end-users to manually toggle privacy settings, push a Domain Group Policy (GPO) or Intune configuration profile to your physical endpoint devices to permanently allow microphone access:

  • GPO Path: Computer Configuration > Administrative Templates > Windows Components > App Privacy
  • Policy Setting: Let Windows apps access the microphone
  • Configuration: Set to Enabled, and under Options, set Default for all apps to Force Allow (or explicitly set desktop app access to Allow).

This overrides Windows' behavior of resetting permissions back to "Off" whenever SlimCore binaries update.

Please refer to this document for step by step: Windows Privacy Compliance: A Guide for IT and Compliance Professionals

Option 2: Manage Teams VDI Update Cadence
If your VDI environment is receiving updates daily or multiple times a day, check your Teams Update Policies in the Microsoft Teams Admin Center:

  • Go to Admin Center > Teams Admin Center > Teams policies > Update policies.
  • Adjust the update channel (e.g., move non-pilot users from Current Channel (Preview) to General) to reduce the update frequency and prevent constant re-registration of the SlimCore plugin.

For further technical details on how SlimCore interacts with local endpoint permissions, you can refer to Microsoft's official guide: Use Microsoft Teams on Azure Virtual Desktop

Please let me know if applying the App Privacy GPO resolves the issue for your endpoints.

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  1. AI answer

    2026-08-13T14:51:30.3366667+00:00

    The behavior described aligns with the SlimCore split-package design, not normal Teams client updates alone.

    With the new SlimCore VDI architecture, the media engine is split into:

    • a Host package with a single Package Family Name: Microsoft.Teams.SlimCoreVdiHost.win-x64_8wekyb3d8bbwe
    • multiple versioned Framework packages

    Microsoft states the single Host package was introduced specifically so that once users grant camera/microphone/location permissions to Microsoft Teams VDI Optimizer, they should not be prompted again when Teams is upgraded in the VM. That means repeated microphone permission resets after updates are not the expected behavior.

    For this scenario, the supported checks are:

    1. Verify the permission is being applied to the Host package on the physical endpoint
      • On the local Windows device, go to Settings > Privacy and security > Microphone.
      • Confirm the permission is for Microsoft Teams VDI / Microsoft Teams VDI Optimizer on the endpoint, not inside the virtual desktop.
      • The documented Package Family Name for policy targeting is Microsoft.Teams.SlimCoreVdiHost.win-x64_8wekyb3d8bbwe.
    2. Preconfigure microphone access by policy instead of relying on user consent
      • Microsoft recommends using Policy CSP - Privacy to preemptively allow access for SlimCore by specifying the Host package family name.
      • Relevant settings are:
        • LetAppsAccessMicrophone_ForceAllowTheseApps
        • optionally also camera/location equivalents if needed
      • This is the most direct way to prevent user-facing permission problems from recurring.
    3. Confirm optimization is actually loading on the endpoint
      • If optimized, MsTeamsVdi.exe should be running on the endpoint.
      • Teams also shows an Optimized banner and indicates whether SlimCore optimization is in use.
      • If Teams is not optimized, users can select ... > Optimize virtual desktop and restart.
    4. Check for endpoint policy or app-control interference
      • Microsoft notes that AppLocker, WDAC, GPO, or application-management policies can affect SlimCore package installation and behavior.
      • Policies called out as potentially blocking the new media engine MSIX packages include:
        • BlockNonAdminUserInstall
        • AllowAllTrustedApps
        • AllowDevelopmentWithoutDevLicense
    5. Collect evidence if the issue continues
      • In Teams Admin Center, Teams client health can surface VDI optimization failure errors and remediation actions.
      • Teams logs can be collected with Ctrl+Alt+Shift+1 in Teams on the VM.

    Based on the documented behavior, this points more toward endpoint privacy policy handling or local package/registration behavior than expected daily Teams updates resetting permissions by design.

    One important limitation: the available documentation here covers Azure Virtual Desktop/Windows 365 and Citrix explicitly. It does not provide VMware/Omnissa-specific confirmation that this exact reset issue is broadly occurring across that platform.

    References:

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