     {setMachineUser} = envHelpers
 
     setMachineUser @mountedMachine, usernames, share, (err) =>
-      if err
-        return  if err.message is 'User not found' and not share
-        return callback err  if err
-
-      @whenRealtimeReady =>
-        @broadcastMessage
-          type: "#{if share then 'Set' else 'Unset'}MachineUser"
-          participants: usernames
+      return callback err  if err
+
+      @broadcastMessage
+        type: "#{if share then 'Set' else 'Unset'}MachineUser"
+        participants: usernames
 
       callback null
 


  handleParticipantAction: (actionType, changeData) ->

    return  unless @rtm

    kd.utils.wait 2000, => @whenRealtimeReady =>

      switch actionType
        when 'join' then @onRealtimeParticipantJoined changeData



  cleanupCollaboration: (options = {}) ->

    kd.utils.killRepeat @pingInterval
    @rtm?.dispose()
