- You sign in to a Microsoft Lync 2010 organization that has a cumulative update for Lync 2010 installed. The cumulative update was released in November 2011 or later.
- You receive a Lync Online meeting invitation from a user in another Lync Server 2010 organization. The Lync Server 2010 organization is non-federated.
- The Dynamic Host Configuration Protocol (DHCP) option is configured to reply to DHCP 120 queries in your organization.
- You try to join a Lync Online meeting.
For more information about the cumulative update for Lync 2010 that is dated November 2011, click the following article number to view the article in the Microsoft Knowledge Base: