Consider the following scenario:
You install Core Components (OcsCore.msi) on a computer that is running Microsoft Lync Server 2013.
You install and then uninstall Windows PowerShell Module for Lync Online (LyncOnlinePowerShell.exe) on the same computer.
In this scenario, Microsoft Online Services Sign-In Assistant (MSOIDCLIL.dll) is uninstalled unexpectedly. Additionally, you cannot move users to Lync Online by running the Move-CsUser cmdlet in Lync Server Management Shell.
When you try to move users, you may receive the following error message:
Move-CsUser : Object reference not set to an instance of an object.
To work around this issue, you must reinstall OcsCore.msi, or reinstall LyncOnlinePowerShell.exe.
OcsCore.msi may be installed when you install one of the following products.
Lync Server 2013
Lync Server 2013 - Administrative Tools
For more information about the update for Windows PowerShell Module for Lync Online, click the following article number to view the article in the Microsoft Knowledge Base:
2955286 Update for Windows PowerShell Module for Lync Online: April, 2014 For more information about how to move users to Lync Online, go to the following Microsoft website: