Enabling the Unified Contact Store for Lync users
The Unified Contact Store (UCS) is automatically enabled on Exchange, and Lync can immediately take advantage of it, but your users won’t be able to access it until you enable it for their use. To be more specific, the Lync policy that controls whether the UCS is available is already set to $True; you can verify this by running the following cmdlet:
Get-CsUserServicesPolicy –id Global
This should show that the UcsAllowed parameter for the default policy is set to $True. When you enable UCS, it becomes available immediately; however, if you later disable it, clients will still use it until you use the Invoke-CsUcsRollback cmdlet, which moves users’ contacts from UCS back to the Lync server-side storage. ...