Open Source Document Management

In LogicalDOC 6.4.1 the version control system, used from the Web GUI, works properly.
Also tested on the demo online which is a 6.4.1 Cloud and it runs as expected.

Are you using a 6.4 version or a 6.4.1 version?
What is your operating system, version of the Java virtual machine, database type and version?

If possible I suggest you to rerun the test,
it could be a problem that has already been fixed in version 6.4.1, even though it seems strange that there's no trace in the issue tracker LogicalDOC Milestone 6.4.1

Document Editing Made Easy
The Document Manager Check In/Check Out feature gives you control over the editing and updating of your documents. Only one person can edit a document at a time, making version control simple and secure. No matter how many people need to edit or update a document, everyone will always have the latest version.
Simple Content and Version Control
Files are “checked out” by a user and locked during editing. Only one person can edit the document at a time. Once the user is finished with their edits, they simply “check in” the document and the file is automatically updated to the most current version. This easy-to-use and powerful feature eliminates problems managing multiple versions of a document. You control what version is worked on at all times.