Data is lost when you use Microsoft Lync 2013 Management Shell to move conference directories from a Lync 2013 pool to a Skype for Business pool.
To resolve this problem, install Lync Server 2013 Cumulative Update 5 Hotfix 9 (build 5.0.8308.887). This cumulative update contains a hotfix to prevent conference directory moves that are made by using Lync Server 2013 Management Shell if the destination is a Skype for Business Server pool.
For more information, click the following link to go to the article in the Microsoft Knowledge Base:
To work around this problem, administrators must use the Skype for Business Management Shell to move conference directories from Lync 2013 pools to Skype for Business pools.