ThinKiosk Restart Privileges
This article will outline the "User Right Assignment" needed for the ThinKioskUser account. #TK-KB6
The ThinKioskUser account is only a member of the ‘Users’ group, hence the restart or shutdown might not be a privilege assign to it.
To overcome this limitation please add the Users group to the "Shut down the system" policy, as illustrated in the screen shot below.