With a recent move to Lync Online, I notice most of my contacts with Microsoft are no longer working – showing Presence Unknown. After much troubleshooting, we’ve decided to lodge an incident to the Microsoft Office 365 Technical Support, in which they came back with a feedback that they’ve did something at the backend and the Federation should work by now.

However, the contacts at my Lync Client shows that “Updating…” and later changes to Presence Unknown.

Finally, manage to get this sorted out by:

  1. Remove all of the contacts that shows as Updating or Presence Unknown
  2. Sign-Out and select “Delete My Sign-in Info”
  3. Deleted all folders under C:\Users\<Username>\AppData\Local\Microsoft\Office\15.0\Lync

Upon signing back to the Lync Client, re-adding the users brings the Presence back to its normal state