Users are unable to modify their contact lists in Lync 2010 and Lync for Mac 2011

Issue:

When you try to edit your contacts in Lync 2010 or Lync for Mac 2011, you receive one of the following error messages:

"Cannot add, move, or remove contacts or groups at this time. Please try again later."

"Your contact list cannot be edited in UCS mode using Microsoft Lync for Mac. Please contact your system administrator."

Resolution:

We moved the contacts from UCS to Skype For Business server

We ran the below PowerShell commands in the Windows Power Shell, after which the contacts were rolled back to Skype for business server: 

• Set-ExecutionPolicy Unrestricted (Y after that to accept).
• Import-Module LyncOnlineConnector
• $cred = Get-Credential (Enter your administrator credentials here)
• $CSSession = New-CsOnlineSession -Credential $cred
• Import-PSSession $CSSession –AllowClobber
• Invoke-CsUcsRollback –Identity (SIP address)