Unusual Briefcase Checkout Situation

One of my users checked out a file using Zimbra Desktop 7.1

The file was checked out to local@host.local, but we have no users with that address. None of our installs will allow us to check the file back in. We can upload new versions, but the file still remains checked out status. The menu popup that usually displays check-in has 2 dividers with no command in-between.

Does anybody know if there is a way to force undo the checkout from the command line, and how to avoid this situation in the future?

Upon further investigation, the faulty checkout appears only on the user's desktop client, but not the web client. The only solution I have is to resync the mailbox, and is not ideal as that takes hours.

This is a bug
Bug 64695 – Checking out a briefcase file under ZCS account leaves the user t unable to check-in or discard the check-out in ZD

I'm having identical issues, OSX Zimbra Desktop, Checkout doesn't actually checkout the item on the server. Except the desktop thinks it has, So when you try check it back in it, there is no option to do so.

Ill test with Windows Zimbra desktop shortly.

Same issues with Windows Desktop.