Troubleshooting the VDI 2.0 solution for Teams

Publisher

Microsoft

URL

https://learn.microsoft.com/en-us/microsoftteams/vdi-2-troubleshooting

Published

2026-07-28

Updated

unknown

Accessed

2026-10-02

HTTP status

200

License

Microsoft Learn terms of use; no-redistribution; short excerpts and locators only

Source notes citing this source

• On an Azure Virtual Desktop endpoint, Microsoft says to confirm that the msrdc.exe process has loaded MsTeamsPluginAvd.dll. in context
• On a Citrix endpoint, Microsoft says to use Process Explorer to confirm that the wfica32.exe process has loaded MsTeamsPluginCitrix.dll. in context
• For Teams SlimCore optimization on Citrix, the Virtual Channel Allow List policy in Citrix Studio must allow the custom virtual channels MSTEAMS, MSTEAM1 and MSTEAM2; if they are blocked, Teams logs error 2003 (deployErrc 16026). in context
• In Vdi_debug.txt, connectedStack "local" means the virtual channel connection failed and the user is in fallback mode; "remote" means Teams reached the endpoint over the virtual channel, but it does not guarantee the calling stack initialised. in context
• A Teams VDI deploy error (deployErrc) happens while the plugin downloads the SlimCore MSIX from Microsoft's CDN and stages it through the App Readiness Service; a load error (loadErrc) happens while starting MsTeamsVdi.exe and opening an RPC to it. in context
• Teams VDI error 1260 (deployErrc 10083, Event Viewer 0x800704EC) usually means Windows Package Manager cannot install the SlimCore MSIX, often because of AppLocker; the fix is to disable AppLocker or add an exception for SlimCoreVdi packages. in context
• Microsoft names the BlockNonAdminUserInstall policy (including the Intune 'Block non admin user install' setting) as the most likely cause of Teams VDI error 16389 (E_FAIL); when it applies, SlimCore registration aborts and the call falls back to non-optimized or, where available, WebRTC. in context
• Teams VDI error 1722 (RPC server unavailable) commonly occurs on slow thin clients overloaded at logon or with delayed AppX registration; Microsoft says to treat it as transient if optimization eventually succeeds. in context
• Teams VDI error 2004 (deployErrc 16032) means the Citrix Workspace app version on the endpoint is not supported and must be upgraded. in context
• When Teams runs as a Citrix published app or an AVD/Windows 365 RemoteApp (error 2005 / 16043), Teams does not load SlimCore and the user is always optimized with WebRTC. in context
• Teams VDI codes 3000 (deployErrc 24002, SlimCore deployment not needed) and 3001 (24010, SlimCore already loaded) are not errors; they show the user is on the SlimCore architecture. in context
• Teams VDI error 403 (deployErrc 3227) means something on the network, typically a proxy, is blocking the SlimCore MSIX download; 404 (3235) points to a missing CDN package or proxy interference. in context
• Teams VDI error 4390 (ERROR_NOT_A_REPARSE_POINT) is a SlimCore MSIX error seen on thin clients that use Unified Write Filters and RAM-disk overlays. in context
• Teams VDI connect and disconnect events are logged in the VM's Windows Logs\Application under source 'Microsoft Teams VDI', Event ID 0; filtering by that source first requires registering it with New-EventLog from an elevated PowerShell. in context
• When Teams SlimCore-based VDI optimization fails to initialise, users can end up in a fallback mode reported as "SlimCore Media Not Connected" (server-side rendering), distinct from being optimized on the legacy WebRTC stack. in context
• If a Teams VDI user sees "Azure Virtual Desktop Media Optimized" or "Citrix HDX Optimized" instead of SlimCore, they are on the legacy WebRTC stack, and error codes 2000 (No Plugin) and 2003 (Virtual Channel not allowed) are the most likely causes. in context
• Teams VDI logs are collected by pressing Ctrl+Alt+Shift+1 in Teams on the VM; Vdi_debug.txt inside the resulting PROD-WebLogs zip is the main file for VDI information. in context
• When Teams shows "Azure Virtual Desktop SlimCore Media Not Connected" or "Citrix SlimCore Media Not Connected", Microsoft names MSIX or AppX deployment errors as the most likely cause. in context
• Microsoft lists SlimCore Host/Framework registration mismatch and the shared-kiosk multi-user registration issue as causes of Teams VDI error 16389 that are fixed in plugin version 2026.29.1.4. in context
• Vdi_debug.txt records the version-mismatch evidence for Teams VDI: bridgeVersion (tied to the Teams client on the VM), remoteSlimcoreVersion (SlimCore on the endpoint), pluginVersion (plugin in the remote desktop client) and rdClientVersion. in context
• The first time Teams detects the endpoint plugin, it needs one restart to move from WebRTC to SlimCore optimization. in context
• The Teams client health page in the Teams admin center lists 'VDI optimization failure' errors with descriptions and remediation actions on its Issues tab. in context

Cite this source record

APA

WarmTransfer. (2026, July 28). Troubleshooting the VDI 2.0 solution for Teams. WarmTransfer. https://warmtransfer.net/knowledge/sources/ms-learn-teams-vdi2-troubleshooting

BibTeX

@misc{warmtransfer-ms-learn-teams-vdi2-troubleshooting,
  title  = {Troubleshooting the VDI 2.0 solution for Teams},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sources/ms-learn-teams-vdi2-troubleshooting},
  note   = {Microsoft, accessed 2026-10-02}
}