We upgraded Zimbra to 7.1.1, and an Outlook user reported this error message:

Zimbra Outlook Connector License Failure
Zimbra Connector for Outlook is not compatible with this edition of the Zimbra Collaboration Server. Please visit our website to find out more.

The issue was resolved with this sequence:
- Closed Outlook and rebooted
- Opened Outlook, and it indicated a server update was required
- OK'd that message
- It then wanted to reboot
- When it came back up all was normal and functioning

The laptop owner was on the road so I didn't get to see any of this first hand. Thought I'd post this in case it's accurate enough to be helpful.