Symptoms
Assume that a user selects the Meet Now option in Microsoft Skype for Business 2015 (Microsoft Lync 2013) to create a meeting and then adds two other participants to the meeting. When one of the invited users starts a video call, the Meet Now user escalates to the video conference but cannot see videos from the other two users.
Resolution
To fix this issue, install the April 4, 2017, update (KB3178731) for Skype for Business 2015 (Lync 2013).
Note Lync 2013 was upgraded to Skype for Business in April 2015.