Focused Inbox Disappeared! (Microsoft Outlook of Mac)

Outlook was offline. There's a message in the bottom-right corner of the window that either says "Connected to [email protected]" or "Outlook is Offline".

When I hit Send/Receive, I was prompted to activate Outlook. Since the license is part of a corporate subscription, that was just matter of entering my password to log in.

Once I did that, the Focused Inbox and ribbon button came back. I'm not sure if it was activating the software or connecting to the server that made the difference.

Another possibility... in the left column section, you may have been looking at the Inbox under "All Accounts" rather than under your "Office365" account (usually listed as your email address). You'll notice that if you click between the two inboxes, your Focused Inbox will disappear/reappear.