Article ID: 2666341 - View products that this article applies to.
Consider the following scenario:
This issue occurs because of an automatic directory synchronization issue. The DL is not assigned a prinID. Therefore, the server does not detect the users in the DL and does not send the invitation.
Note The term DL can refer to a distribution list, security group, organizational unit and so on.
To resolve this issue, install the following cumulative update:
(http://support.microsoft.com/kb/2670342/ )Description of the cumulative update for Lync Server 2010, Group Chat: February 2012
(http://go.microsoft.com/fwlink/?LinkId=151500)for other considerations.