Can't automatically log on to Skype for Business 2015 (Lync 2013) that has December 6, 2016 update installed Content provided by Microsoft Applies to: Skype for Business 2015Microsoft Lync 2013 Select Product Version All Products Symptoms When you try to sign in to Microsoft Skype for Business 2015 (Lync 2013) that has December 6, 2016, update applied, you stuck in the sign-in process. Resolution To fix this issue, install the October 10, 2017, security update for Skype for Business 2015 (Lync 2013) (KB4011179).Note Lync 2013 was upgraded to Skype for Business in April 2015. Last Updated: Oct 10, 2017 Was this information helpful? Yes No Tell us what we can do to improve the article Submit Thanks! Your feedback will help us improve the support experience.