Okay, I made this post because this can be a very frustrating issue to deal with. The scenario is that you may have created a voice policy or dial plan, attached them to a user and then you later delete them without removing them from the user. The Lync Administration Console will allow you to do this and the result is that you will get a warning in Lync for that user stating “DialPlan” with identity “1″ assigned to (all my Lync enabled users) has been removed from configuration store.”, or something similar.
So now what? You can’t change it in the administration console. What you need to do now is run a commandlet (from the powershell) to set the value for that user.
The first commandlet to run is Get-CsUser -Identity “<whatever username you want to view>” This will tell you details about that user including the dial plan or voice policy. You should also see an error in yellow text similar to the one seen in the administration console.
The second commandlet to run is Grant-CsDialPlan -Identity “<whatever username you want to edit> -PolicyName $null” This will set the user’s dialplan to the global dialplan. The command for changing the users voice policy follows the same syntax “Grant-CsVoicePolicy”
Afterwards you can run the Get-CsUser commandlet and see that the errors are no longer there.