Symptoms
Assume that you deploy the federation feature in a Microsoft Lync Server 2010 environment. Then, a Lync 2010 user tries to invite federated users to a meeting. However, some federated users do not receive the meeting invitation.
Cause
This issue occurs because a variable is not set correctly. This causes an error that indicates that federation is disabled globally. Therefore, an SQL stored procedure does not work.
Resolution
To resolve this issue, install the following cumulative update:
2670334 Description of the cumulative update for Lync Server 2010, Core Components: February 2012