Enhanced 911 (E911) calls using Skype for Business 2016 on Mac don't work through the non-Windows authentication in Skype for Business Server 2015 Content provided by Microsoft Applies to: Skype for Business Server 2015 Select Product Version All Products Symptoms E911 calls don't work in Skype for Business 2016 on Mac when the non-Windows authentication (such as ADFS) is used to authenticate the Microsoft Skype for Business server. Resolution To fix this issue, install the February 2017 cumulative update 6.0.9319.277 for Skype for Business Server 2015. Last Updated: Mar 1, 2017 Did this solve your problem? Yes No Tell us what we can do to improve the article Submit Thanks! Your feedback will help us improve the support experience.