On Tuesday, April 14, Microsoft released the patch that changes the Lync Client UI to Skype for Business. The patch can be found here: https://support.microsoft.com/en-us/kb/2889923, and it is also available via Windows Update. We have had a few calls on preventing users from using the new UI. It turns out, you can prevent your users from using the new UI, as well as force them to use the new UI. The following commands must be run using Lync Powershell on your front end server.
To force new Skype for Business UI, run the following command: Set-CsClientPolicy -Identity Global -EnableSkypeUI $true
To prevent Skype for Business UI, run the following command: Set-CsClientPolicy -Identity Global -EnableSkypeUI $false
You can also do this based on site and user group. Those details can be found in the following technet article: https://technet.microsoft.com/en-us/library/dn954919.aspx
This does require Lync Server 2013 to be patched to the December 2014 Cumulative Update (5.0.8308.857). If you need assistance upgrading your Lync Server to the latest CU, or have questions about Skype for Business, feel free to contact us!
Andy Shaffer, PEI