Cyberduck Mountain Duck CLI

Version 29 (modified by dkocher, on Mar 5, 2020 at 8:43:39 AM) (diff)


Cyberduck Help / Howto / Mountain Duck / File Locking

Preliminary documentation. Version 3.4 or later required

Mountain Duck supports locking files to prevent conflicting edits from others while a document is open in a editor.

Lock Support in WebDAV

WebDAV supports locking files on the server. Mountain Duck locks files on the server when opened in a editor. This prevents other users from modifying the document until the file is closed by the user.

Note: Some WebDAV implementations including ownCloud and NextCloud may not support locking documents.

Pseudo locking for protocols with no native lock support using lock owner files

For connections other than WebDAV, we support detecting files opened by others by looking for owner lock files uploaded to the server.

Note: Support is currently limited to files edited in Microsoft Word, Microsoft Excel and Microsoft Powerpoint on macOS and Windows.


When a previously saved file is opened for editing, for printing, or for review, Word creates a temporary file that has a .doc file name extension. This file name extension begins with a tilde (~) that is followed by a dollar sign ($) that is followed by the remainder of the original file name. This temporary file holds the logon name of person who opens the file. This temporary file is called the "owner file."

Error message when opening locked document

Attempting to open a locked document, an error message is displayed notifying the document can only be opened in read only mode. Samples of error messages from different applications.

Microsoft Word (Windows)

This file is already opened by another user. Would you like to make a copy of this file for your use?

Choose Receive notification when the original copy is available to open the document in read-only mode and get an alert when the other user has closed the document.

Microsoft Word (macOS)

Read Only. To save a copy of this document, click Duplicate

Microsoft Excel (Windows)

File in Use: File is locked for editing by …. Open 'Read-Only' or click 'Notify' to open read-only and receive notification when the document is no longer in use.

Choose Notify to open the document in read-only mode and get an alert when the other user has closed the document.

Libre Office (macOS)

Document … is locked for editing by…. Open document read-only or open a copy of the document for editing.


If you get a warning that the document is Read-Only, ask other uses to close the document. If the Read-Only warning prevails, these are the steps to follow.

  • If you are connecting to a WebDAV server with lock support, ask the server administrator to cleanup locks on the server.
  • For all other servers, delete the file named ~$….


Refer to Preferences.