New VDI solution for Teams

The new VDI solution for Teams is a new architecture for optimizing the delivery of multimedia workloads in virtual desktops.

System requirements

Components

Optimizing with new VDI solution for Teams

Step 1: Confirm prerequisites

1. Make sure you have the new Microsoft Teams version 24193.1805.3040.8975 or higher (for Azure Virtual Desktop/Windows 365), 24295.605.3225.8804 or higher for Citrix, or 26032.206.4355.6508 for Omnissa.

2. Enable Teams policy if necessary for a specific user group (it's enabled by default at a Global org-wide level).

3. For Citrix, you must configure the Virtual channels allow list as described in the Citrix Virtual channel allow list section of this article.

4. For Amazon WorkSpaces, make sure the WorkSpace client for Windows is 5.31.0.5733 or higher.

5. For Omnissa Horizon, optimization is now generally available - make sure the Horizon client for Windows is 8.17 (2512) or higher.

Step 2: Plugin installation on the endpoint

1. For Azure Virtual Desktop and Windows 365, MsTeamsPluginAvd.dll is bundled with the Remote Desktop Client for Windows 1.2.5405.0, with the Windows App Store app for Windows 1.3.252 or higher, and with the Windows App for MAC Non-Store version 11.3.4

   • The plugin is found in the same folder location where the Remote Desktop Client is installed. You can find the plugin at AppData\Local\Apps\Remote Desktop or C:\Program Files (x86), depending on the mode in which it was installed.
   • The Windows App Store app, which is MSIX-based, is found in C:\Program Files\WindowsApps. Access to this folder is restricted.

2. For Amazon WorkSpaces, MsTeamsPluginAmazon.dll is bundled with the WorkSpaces Client for Windows 5.28.0.5487 or higher.

   • The plugin is found in the same folder location where the WorkSpaces Client is installed.

3. For Omnissa Horizon, MsTeamsPluginOmnissa.dll is bundled with the Horizon Client for Windows 8.17 (2512) or higher.

   • The plugin is found in the same folder location where the Horizon Client is installed (C:\Program Files\Omnissa\Omnissa Horizon Client).

4. For Citrix Workspace app for Windows 2402 or higher, MsTeamsPluginCitrix.dll can be installed either:

   • Using the user interface when installing Citrix Workspace app:

     On the Add-on(s) page, select the Install Microsoft Teams VDI plug-in checkbox, and then select Install.

     Agree to the user agreement that pops up and proceed with the installation of the Citrix Workspace app.

     Note

     Citrix Workspace app for Windows 2402 only presents the plugin installation UI on a fresh install.
     For in-place upgrades to also present this option, Citrix Workspace app for Windows 2405 or Mac 2603 higher is required.
     Automatic installation of the plugin when CWA is auto-updating was introduced in CWA for Windows 2508.
     Starting from Citrix Workspace app 2603 for Windows, CWA can auto-update the plugin to the latest version, even before CWA auto-updates to a newer version.
     For more information, check this Citrix article

   • Via command line or scripts for managed Windows devices using C:>CitrixWorkspaceApp.exe /installMSTeamsPlugin

• Admins can also install the plugin manually on top of any existing supported Citrix Workspace app (see System Requirements) using tools like SCCM (use the Windows app package deployment type) or Intune (use the Line-of-Business app).

  Admins can use msiexec with appropriate flags, as discussed in msiexec.

  Important

  • Windows Plugin MSI download link for Citrix customers:
    - For 32-bit Workspace app aka.ms/plugin.
    - For 64-bit Workspace app (new) aka.ms/plugin_x64.
    - For arm-based Workspace app https://aka.ms/plugin_arm64.
    - Citrix Workspace app (wfica process) can only load plugins from the same architecture (in other words, 32-bit CWA loading 64-bit DLL will fail to optimize)
  • Mac Plugin download link for Citrix customers aka.ms/macplugin

• The plugin MSI automatically detects the CWA installation folder and places MsTeamsPluginCitrix.dll in that location.

• Plugins can only be upgraded while there's no active Virtual Desktop session.

• Plugins can't be downgraded, only upgraded or reinstalled (repaired).

• Per-user installation of CWA isn't supported.

• If no CWA is found on the endpoint, installation is stopped.

Step 3: SlimCore MSIX staging and registration on the endpoint

The plugin silently executes this step, without user or admin intervention. The staging and registration relies on the App Readiness Service (ARS) on the endpoint. It's possible that registry keys set by a Group Policy or a third-party tool block the MSIX package installation. For a complete list of applicable registry keys, see How Group Policy works with packaged apps - MSIX.

The following registry keys could block new media engine MSIX package installation:

• BlockNonAdminUserInstall
• AllowAllTrustedApps
• AllowDevelopmentWithoutDevLicense

These three registry keys can be found at either of the following locations on the user's device:

• HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock
• HKLM\SOFTWARE\Policies\Microsoft\Windows\Appx

Some policies might change these registry keys and block app installation in your organization because the admins set a restrictive policy. Some of the known GPO policies that could prevent installation include:

• Prevent non-admin users from installing packaged Windows apps.

• Allow all trusted apps to install (disabled).

Mac endpoints

Users that meet the minimum requirements described earlier in this article can be optimized using the new architecture (SlimCore-based).

AVD and Windows 365 customers must use the nonstore Windows App version (also known as the Microsoft AutoUpdate or MAU client), since only that version bundles the Plugin. App Store Windows App doesn't include the Plugin, therefore users will remain in the WebRTC-based optimization. Evergreen link to the latest MAU client: https://aka.ms/RDMacMAU

For Citrix customers, CWA 2508.10 can present a User Interface upon installation that prompts the user to install the Plugin, but this flow requires user action. CWA 2603 also supports plugin deployment via Global App Config Service, or the Virtual Channel Plugin Download Manager policy in Citrix Studio.
An upcoming version of CWA (2607) will automatically install the Plugin. Administrators can also deploy the Plugin using other tools like JAMF.

SlimCoreVdi installation folder

• For AVD/W365, /Users/{USER}/Library/Containers/windows App/Data/Library/Application Support/Microsoft/TeamsVDI/Packages/
• For Citrix, /Users/{User}/Library/Application Support/Microsoft/TeamsVDI/Packages

Log collection in Mac

Logs are stored in the following directory on the user's device: ~/Library/Application Support/Microsoft/TeamsVDI

Unsupported Features in Mac

• HID​ (currently only available in Public Preview)
• Townhall optimization as an attendee
• For AVD/W365, Cross Cloud is currently not supported
• Outgoing screen sharing in end-to-end encrypted meetings is disabled​
• Share system audio
• Authenticated Proxies in macOS Network settings (AVD/W365 only)
• Link Layer Discovery Protocol (LLDP) in e911 (AVD/W365 only)
• Remote App / Published Apps

Known Issues in Mac

1. Presenter's mouse cursor is slow during app sharing. If the presenter stops and reinitiates app sharing, the lag is not present anymore. This is fixed in Teams 26149.x.x.x or higher.

2. Zoom VDI plugin older than 6.6.10 on the Mac device results in a Citrix Workspace app crash on call transfers.

3. If you attach/detach external monitors during the call, video might appear on the wrong screen. This also occurs when you change display alignments during the HDX session​.

Verifying that the endpoint is optimized

Once you meet all the minimum requirements, launching Teams for the first time will attempt to load in SlimCore optimized mode, by default.

You can check in the Teams client that you're optimized with the new architecture by looking at the VDI Status Indicator (top left in the UI). Also, users can select the ellipsis (three dots ...) on the top bar, then selecting Settings > About. The Teams and client versions are listed there.

• AVD SlimCore Media Optimized = New optimization based on SlimCore.
• AVD Media Optimized = optimization based on WebRTC.

The plugin (MsTeamsPluginAvd.dll, MsTeamsPluginCitrix.dll, or MsTeamsPluginAmazon.dll) is responsible for eventually downloading the media engine, and SlimCore, which is an MSIX package. It installs silently without admin privileges or reboots in (example, exact path varies):

C:\Program Files\WindowsApps\Microsoft.Teams.SlimCoreVdi.win-x64.2024.15_2024.15.1.5_x64__8wekyb3d8bbwe

For the new Split MSIX Package: C:\Program Files\WindowsApps\Microsoft.Teams.SlimCoreVdiFwk.win-x64.2025.28_2025.28.1.4_x64__8wekyb3d8bbwe C:\Program Files\WindowsApps\Microsoft.Teams.SlimCoreVdiHost.win-x64_2025.28.1.4_x64__8wekyb3d8bbwe

The remote desktop client or the Citrix Workspace app downloads the x64 or x86 SlimCore package, based on the user's device. The 'WindowsApps' folder is locked down, so users don't have access to it. Admins modify ACLs to take ownership, though this action isn't recommended. Instead, use PowerShell to list the MSIX apps in the endpoint:

PowerShellCopy

Get-AppxPackage Microsoft.Teams.SlimCore*

A sample of the results that can be returned from running this PowerShell is:

Name              : Microsoft.Teams.SlimCoreVdiHost.win-x64
Publisher         : CN=Microsoft Corporation, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
Architecture      : X64
ResourceId        :
Version           : 2026.20.1.7
PackageFullName   : Microsoft.Teams.SlimCoreVdiHost.win-x64_2026.20.1.7_x64__8wekyb3d8bbwe
InstallLocation   : C:\Program Files\WindowsApps\Microsoft.Teams.SlimCoreVdiHost.win-x64_2026.20.1.7_x64__8wekyb3d8bbwe
IsFramework       : False
PackageFamilyName : Microsoft.Teams.SlimCoreVdiHost.win-x64_8wekyb3d8bbwe
PublisherId       : 8wekyb3d8bbwe
IsResourcePackage : False
IsBundle          : False
IsDevelopmentMode : False
NonRemovable      : False
IsPartiallyStaged : False
SignatureKind     : Developer
Status            : Ok

Name              : Microsoft.Teams.SlimCoreVdiFwk.win-x64.2026.20
Publisher         : CN=Microsoft Corporation, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
Architecture      : X64
ResourceId        :
Version           : 2026.20.1.7
PackageFullName   : Microsoft.Teams.SlimCoreVdiFwk.win-x64.2026.20_2026.20.1.7_x64__8wekyb3d8bbwe
InstallLocation   : C:\Program
                    Files\WindowsApps\Microsoft.Teams.SlimCoreVdiFwk.win-x64.2026.20_2026.20.1.7_x64__8wekyb3d8bbwe
IsFramework       : True
PackageFamilyName : Microsoft.Teams.SlimCoreVdiFwk.win-x64.2026.20_8wekyb3d8bbwe
PublisherId       : 8wekyb3d8bbwe
IsResourcePackage : False
IsBundle          : False
IsDevelopmentMode : False
NonRemovable      : False
IsPartiallyStaged : False
SignatureKind     : Developer
Status            : Ok

If you're optimized, you can see MsTeamsVdi.exe running on your endpoint for Azure Virtual Desktop/W365 (as a child process of msrdc.exe) or Citrix (as a child process of wfica32.exe). When using Process Explorer, If you select msrdc.exe (or wfica32.exe), select Show the lower pane under View and switch to the DLL tab, you can also see the Plugin (MsTeamsPluginAvd.dll or MsTeamsPluginCitrix.dll) being loaded. This action is a useful troubleshooting step in case you're not getting the new optimization.

VDI Status Indicator

Microsoft Teams displays information about the optimization status, helping the user understand if they're optimized or not. It also shows if they're using the WebRTC optimization or the new Slimcore-based one by hovering their cursor over the Optimized banner.

In cases where Microsoft Teams isn't optimized, the user sees a warning icon.

Users can select the three dots and choose Optimize virtual desktop and restart to attempt a repair.

This selection triggers a Teams restart, which can solve some known issues. If the user is still unoptimized, an error code displays for quick diagnosis by IT Admins based on the connection error table.

Users are presented with a link to receive more information about the error, and if it's actionable, they can try a self-remediation.

Session roaming and reconnections

For example, a Windows endpoint used in bring your own device (BYOD) scenarios while working from home that has the plugin installed, and a corporate-managed Linux thin client in the office that only supports WebRTC. When the user roams between the two endpoints, Teams will automatically pick the right optimization stack without asking the user to restart the application. Additionally, the user is notified about the optimization switch with a dismissible banner ("Optimizing virtual desktop ...").

This seamless stack transition replaced the modal dialogue that asked the user to manually restart the app in VDI environments.

Networking considerations

Network architecture

A walkthrough of the architecture in the diagram:

1. Start Teams.​
2. Teams client authenticates to Teams services. Tenant policies are pushed down to the Teams client, and relevant configurations are relayed to the app.​
3. Teams detects that it's running in a virtual desktop environment and instantiates the internal vdibridge service​.
4. Teams opens a secure virtual channel on the server​.
5. The RDP/HDX/Blast/DVC protocol transports the request to the VDI Client (Windows App, Citrix Workspace app, Horizon Client, or Amazon WorkSpaces) that previously loaded MsTeamsPlugin (client-side virtual channel component)​.