Assume that user A's display name is configured to have special characters in Active Directory. When you start and end a Skype call with user A in Microsoft Skype for Business 2016 or Skype for Business 2015 (Lync 2013), you may find the notifications in the conversation window show user A's display name with an emoticon. For example, "Connected to user A (an emoticon)" and "Call with user A (an emoticon) has ended."
To fix this issue, install one of the following updates:
For Skype for Business 2016, install the August 7, 2018, update (KB4032255).
For Skype for Business 2015 (Lync 2013), install the August 7, 2018, update (KB4032250).
Note Lync 2013 was upgraded to Skype for Business in April 2015.