Move the unzipped application bundle Mountain from the Downloads to the /Applications folder on your computer.


No admin privileges for installation is required.

Mac App Store
Mountain Duck is installed through the Mac App Store in /Applications. You can always reinstall Mountain Duck on any Mac you own from the Mac App Store in → App Store… → Purchased.

Login Item
You can choose to open Mountain Duck when you log into your computer. The application will appear in Login Items of the User & Groups system preferences panel.

Login Item

Finder Extension
Enable the Mountain Duck Finder Extension in System Preferences → Extensions → Finder by selecting the checkbox. This will enable:

  • Context menu items for files selectec on a mounted volume with options to Reload the folder listing and copy & open URLs of files

  • Badges on file icons to display sync status when Smart Synchronization is enabled for the bookmark


For macOS Ventura and later, the setting can be found in System Settings → Privacy & Security → Extensions → Added Extensions.

Mountain Duck Finder Integration

System Requirements

  • Mountain Duck 3.3.5 or later requires macOS 10.12 or later

  • Mountain Duck 3.0.1 or later requires macOS 10.11 or later

Registration Key

Double-click the file .mountainducklicense to apply the license and register Mountain Duck. Alternatively, you can copy the key file to the application support folder.

You can manually install the registration key in

  • ~/Library/Group Containers/ Support/duck/

Known Issues

Not a Valid Registration Key

This error message appears if you try to use an old license key for a newer version. Upgrade your license to the latest version of Mountain Duck or download an older version from Mountain Duck changelog.

Upgrade Issues

After upgrading a license, a new license file will be generated.

  1. Delete the current license file from the application support folder.

  2. Download the new license file from the email attachment.

  3. Apply the new license file using double-click or copy the file into the application support folder.

Windows Installation

Error Code 0x24C

If you get the error code 0x24C uninstall the client, reboot the system, and reinstall the client.

0x24C. A volume has been accessed for which a file system driver is required that has not yet been loaded.


For troubleshooting purposes when reaching out for support, please share the latest installation log. The installation log file prefixed Mountain Duck_ can be found in %Temp%.

Installation with Device Management Software

You can distribute Mountain Duck with the help of Active Directory or a system management tool like Intune on Windows or JAMF on macOS and copy the license file into the application support folder after installing Mountain Duck. Installation packages are provided in MSI (Windows) and PKG (macOS) formats.


  • Add preconfigured connection profiles and bookmarks this way by copying the connection profile file (.cyberduckprofile) into the Profiles folder or the bookmark file (.duck) into the Bookmarks folder within the application support folder.

  • Share default settings by using the file.


Using Windows Command Line:

  • Regular uninstall: Mountain Duck Installer-<version>.exe /uninstall

  • Silent uninstall: Mountain Duck Installer-<version>.exe /uninstall /quiet

Complete Uninstall

Follow the steps below to uninstall Mountain Duck completely.

  1. Close the application and navigate to the application folder using the shortcut ⌘⇧A. Select Mountain and delete the application by choosing File → Move to Trash.

  2. Navigate to the Group Containers folder within ~/Library/ and delete the folder If you changed the cache location you will have to delete that folder as well.

  3. Run the command to reset and erase the settings for Mountain Duck: defaults delete io.mountainduck

  4. Optional: Delete all saved login credentials regarding Mountain Duck within Keychain