For anyone who didn't install the Skype for Business client upgrade with April patches, be aware that the security update in the May patches includes the updated Skype for Business client.
https://support.microsoft.com/en-us/kb/3039779/ The KB article does state quite clearly that this update includes the client update, so had I read the KB article I could have avoided the update, but . . . In my case, my test group received the Skype4B client update last month, after which I pulled it from the update group before deploying patches to all workstations. Unfortunately, when this month's security update went out to my test group, they all had the new client already, and so there was no noticeable change. As a result, when the update was deployed last night to all workstations, users came in to the Skype4B client and it's popup prompting them to restart it in lync mode. *TLDR: If you aren't ready to deploy the Skype4B client update, don't push out KB3039779. * Steve
