Symptoms
When you have problems in the Microsoft Skype for Business 2015 (Microsoft Lync 2013) client sign-in process, the client may not display an alternative meeting join window to let you join the meeting through a web browser.
Resolution
To fix this issue, install the September 12, 2017, security update (KB4011107) for Skype for Business 2015 (Lync 2013).
Note Lync 2013 was upgraded to Skype for Business in April 2015.
