The Problem: While you work on the file, one of your colleagues also starts working on it. She then saves her changes to the file. Later you also save, unintentionally overwriting her changes and wiping out the progress she has made.
The Solution: With the new ownCloud 10.5, users can explicitly lock files while they work on them. Every user with access to a file can lock it. Locks automatically expire after a certain amount of time, by default after 30 minutes. Before the lock expires automatically, only the user that locked the file can unlock it.
Important: This feature is disabled by default, because it allows users to lock other user’s files *exclusively*, so even the owner can’t unlock them. Before activating this feature, please double-check if this is the behaviour you want. Please see the release notes for information on how to enable it. If you’re fluent in CLI, just enable it through this command:
occ config:app:set files enable_lock_file_action --value yes
Admin docs: doc.owncloud.com
The Admin Angle: You can shorten or lengthen the lock period in their admin section. File locking prevents file conflicts, keeps versioning and activity logging clean and is easy to use through the Web App. File Locking is only available in the Web App for now, but while a file is locked, the Mobile Apps and the Desktop Clients can’t save changes to it.