Configure clients for migration
This topic contains the recommended client deployment steps you should take before migrating to Skype for Business Server 2019. These configuration changes should be made on Lync Server 2013 or Skype for Business Server 2015 (the version you are migrating from).
To configure clients before migration
Deploy the most recent server, client, and device updates (hotfixes) for your existing installation.
On the previous version of Skype for Business Server, use Client Version Filtering to only allow clients with the most current updates installed.