Symptoms
A user signs in to Microsoft Lync 2013 by using an account that has unified contact store (UCS) enabled. In this situation, the user cannot add or remove a contact or a distribution group (DG) that contains special characters, such as "&" (ampersand), in Lync 2013. Additionally, the user cannot create or delete a group that has special characters in Lync 2013.
Resolution
To resolve this issue, install the following update:
2881013 MS14-036: Description of the security update for Microsoft Lync 2013: June 10, 2014