This issue occurs when you do not add a user to your contact list in Microsoft Lync for Mac 2011 that has enhanced privacy mode for Microsoft Lync Server 2013 enabled. When this issue occurs, you cannot see the presence state of the user, and the following options are greyed out in the contact list:
Start a video call
Send an instant message
Note In enhanced privacy mode, the presence state of the users who are not added to your contact list is displayed as Offline in Lync for Mac 2011.