This issue occurs when the domain name of the SIP user is registered as an Organizational ID (OrgID) and Microsoft account (MSA) domain.
Resolution
To fix this issue, install the April 4, 2017, update (KB3178731) for Microsoft Skype for Business 2015 (Lync 2013).
Note Lync 2013 was upgraded to Skype for Business in April 2015.
