When the password protection feature is enabled in Symantec Endpoint Protection 14 RU1 MP2 and LaunchSMCGUI is set to 0, there is no prompt to enter a password when using the smc -stop command. If you set LaunchSMCGUI to 0, the notification area icon does not appear.
This issue is fixed in Symantec Endpoint Protection 14.2 MP1. For information on how to obtain the latest build of Symantec Endpoint Protection, see Download the latest version of Symantec Endpoint Protection.