Windows Server, Terminal Services & Citrix#

Installation and operation of Mountain Duck 5 or later in multi-user environments: Remote Desktop Services (RDS), Citrix Virtual Apps & Desktops, and Windows Server installations.

MSIX Installer Package#

As of version 5.0, Mountain Duck is distributed as an MSIX package (Windows app) and no longer as a classic program installation. For multi-user environments this means:

  • Installation for all users is performed with app provisioning using PowerShell (Add-AppxProvisionedPackage) instead of the graphical installer.

  • Sideloading of trusted apps must be permanently allowed on the server.

  • The downloadable .exe installer is a bootstrapper installing the same MSIX package in the background. On terminal servers it may briefly start and exit without displaying a message. Always use the MSIX Installer Package directly on servers.

Supported Windows Server Versions#

Mountain Duck 5 requires Windows 10 1809 (17763) or later. For server operating systems:

Operating System

Status

Notes

Windows Server 2022 / 2025

Recommended

Fully supported, including context menu items and Integrated connect mode. Recommended basis for terminal servers and Citrix.

Windows Server 2019

Limited

Installation is only reliable using PowerShell provisioning. Context menu items in Windows Explorer are not available because the operating system lacks PackagedCom support for MSIX apps; core functionality (mounted volume, synchronization) is not affected. Use Mountain Duck 5.3.1 or later — earlier versions have a known defect when updating or provisioning on Server 2019.

Windows Server 2016

No 5.x

Build 14393 is below the minimum requirement of version 5. The last usable product line is Mountain Duck 4.x (4.13 or later, requires .NET Framework 4.7.2).

Windows Server 2012 / 2012 R2

Not supported

The operating system is end-of-life. The last runnable version was Mountain Duck 4.12.5.

Note

The Desktop Experience installation option (graphical user interface) is required on all servers. Server Core installations are not supported.

Prerequisites#

Sideloading#

Sideloading of trusted apps must be allowed to install the MSIX package and to allow the app to launch for all users afterwards. Whether any action is required depends on the operating system — sideloading is enabled by default since Windows 10 2004:

System

Sideloading by Default

Required Action

Windows Server 2019 (Build 1809)

Disabled

The policy must be explicitly enabled (see below). Not configured effectively means disabled here.

Windows Server 2022 / 2025

Enabled

None — verify that no enterprise policy disables sideloading.

Windows 10 (2004 or later) / Windows 11

Enabled

None — verify that no enterprise policy disables sideloading.

Enable sideloading on Windows Server 2019 using one of the following options:

  • Group Policy: gpedit.msc → Computer Configuration → Administrative Templates → Windows Components → App Package Deployment → Allow all trusted apps to install

  • Registry (for scripts, in an elevated PowerShell):

Set-ItemProperty HKLM:\Software\Policies\Microsoft\Windows\Appx -Name AllowAllTrustedApps -Value 1 -Type DWord

In managed environments (GPO/Intune) the default can be overridden on any system: a policy enforcing AllowAllTrustedApps=0 blocks installation and launch on Windows 11 and Server 2022/2025 as well. When in doubt, verify the effective value:

Get-ItemProperty HKLM:\Software\Policies\Microsoft\Windows\Appx -Name AllowAllTrustedApps

Warning

Do not reset the setting after the installation. If AllowAllTrustedApps is set back to 0, users can no longer launch the installed app (it is listed in Windows Settings with a size of 0). In environments where this policy must remain disabled, version 5 can currently only be deployed from the Microsoft Store or as an Intune line-of-business (LOB) app.

Unsupported Configurations#

  • RemoteApp / published single applications: Mountain Duck is a tray application. RemoteApp sessions do not transfer the notification area — deployment as a single RemoteApp or published Citrix app is not supported. Deploy Mountain Duck in full desktop sessions only.

  • FSLogix profile containers: Microsoft explicitly does not support MSIX/Store apps in FSLogix containers. FSLogix environments show corrupted app package folders and crashes on launch. If FSLogix is in use, refer to Troubleshooting AppX/MSIX with FSLogix; compatibility cannot be guaranteed.

Installation#

Preparation#

  1. Uninstall an existing Mountain Duck 4.x installation using Apps & Features.

  2. Verify sideloading and enable it if necessary (mandatory on Server 2019).

  3. Sign out all other users from the server. Provisioning fails while other users are signed in — the most common cause of failure on terminal servers.

  4. Download the MSIX Installer Package from the official download page (do not use the .exe installer).

Machine-wide Installation#

In an elevated PowerShell:

Add-AppxProvisionedPackage -Online -SkipLicense -LogPath "$env:Temp\MountainDuck-msix.log" -PackagePath "Mountain Duck_x.x.x.xxxxx_x64.msix"

This provisions the package for all user profiles. The actual registration takes place per user at the next sign-in — the app appears in the Start menu with a short delay.

Citrix with gold/master image: Perform the provisioning in the image (interactively with -Online as above, or offline against the mounted image):

Add-AppxProvisionedPackage -Path "X:\Mount" -SkipLicense -PackagePath "Mountain Duck_x.x.x.xxxxx_x64.msix"

Support Package (Driver & Shell Extension)#

Connecting using Online or Smart Synchronization connect mode additionally requires a file system driver and Windows Explorer integration. The package is included in the MSIX and is installed machine-wide:

msiexec /i "$((Get-AppxPackage -AllUsers io.mountainduck).InstallLocation)\Setup\Mountain Duck Support.msi" /qn /l*v "$env:Temp\MountainDuck-support.log" ALLUSERS=1 REBOOT=ReallySuppress

Note

No driver is required in Integrated connect mode (Windows Cloud Files API) — the support package can be omitted in this case. This makes Integrated the least invasive option on terminal servers.

Verify Installation#

Get-AppxPackage -AllUsers io.mountainduck

Manual launch (e.g. from a logon script):

start shell:AppsFolder\$((Get-AppxPackage io.mountainduck).PackageFamilyName)!App

Sign in with a test user, wait for the app registration to complete, and verify that a connection can be configured and the mounted volume is accessible.

Updates#

  • Do not use the built-in update function or the .exe installer on terminal servers. Install updates like the initial installation: provision the new MSIX using Add-AppxProvisionedPackage with no users signed in.

  • In Citrix environments, update the gold image and redeploy.

  • When upgrading from 4.x to 5.x, the automatic updater also installs the support package without asking. To control this (e.g. for Integrated connect mode without the driver), uninstall 4.x and install 5.x manually using the MSIX package.

  • On Windows Server 2019, always use version 5.3.1 or later.

Recommendations#

  • Keep the drive letter set to Auto. In Citrix environments, fixed drive letter assignments have been observed to cause connection drops that disappeared after switching to Auto.

  • Choose the connect mode deliberately: Integrated requires no driver; Online and Smart Synchronization require the support package and the file system driver.

  • Never create package folders manually. Creating missing folders below %LocalAppData%\Packages\ by hand results in incorrect permissions (ACLs) and crashes of the app. Such errors indicate a provisioning or profile problem that must be fixed at its cause.

  • Antivirus/security agents: Third-party real-time scanners can significantly degrade Windows Explorer performance on the mounted volume. Add the Mountain Duck volume and the local cache to the exclusions.

  • Roaming profiles: Configuration and logs are stored in the user profile (the %AppData% part roams).

Troubleshooting#

Symptom

Cause / Resolution

Installer briefly starts and exits without a message

The .exe bootstrapper fails at the MSIX deployment. Install the MSIX directly using Add-AppxProvisionedPackage.

Add-AppxProvisionedPackage fails

Other users are signed in to the server — sign out all sessions and retry.

App only launches for the installing administrator; listed with a size of 0 for other users

AllowAllTrustedApps was reset after the installation or is overridden by a policy. Set the value permanently to 1.

App does not start automatically after signing out and back in

Verify the autostart of the app in desktop sessions; in special cases launch it from a logon script: start shell:AppsFolder\<PackageFamilyName>!App

Error code 0x24C when loading the file system driver

Uninstall the client, reboot the server, and reinstall.

Crash with event log entry Microsoft-Windows-AppModel-State, error -2147024809 (E_INVALIDARG)

Corrupted app package folder in the user profile (typical with FSLogix or manually created folders). Clean up the user profile; verify FSLogix compatibility.

Logs for Support#

  • MSIX deployment: Event Viewer → Applications and Services Logs → Microsoft → Windows → AppXDeployment(-Server) → Operational, plus the log created with -LogPath.

  • Support package: the log created with msiexec /l*v; installation logs prefixed Mountain Duck_ in %Temp%.

  • Application logs: in the user profile (with roaming profiles, in the roaming part on the terminal server). Refer to the support page.