Symptoms
This issue occurs when you move users from Office Communication Server (OCS) 2007 to Microsoft Lync Server 2013. Additionally, you may receive an error message that resembles the following:
Move-CsLegacyUser : Object reference not set to an instance of an object. At line:1 char:1
+ Move-CsLegacyUser xxxx -domain.com +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [Move-CsLegacyUser], NullReferenceException + FullyQualifiedErrorId : System.NullReferenceException,Microsoft.Rtc.Management.AD.Cmdlets.MoveOcsLegacyUserCmdle TCause
This issue occurs because an access violation exception is raised when handling the move request.
Resolution
To fix this issue, install the January 2017 cumulative update 5.0.8308.984 for Lync Server 2013.