If your kiosk starts showing this message, please reboot the tablet by tapping 10 times on the version number on the "home" (Do you want to wash or dry) screen, in the lower-right corner. Otherwise you can restart Kiosk by taking it out of its frame and holding the power button for a few seconds until "Do you want to restart?" is shown.
Alternatively, you can contact Tangerpay Support to have the tablet rebooted remotely.
If your are experiencing this issue very frequently, please let us know so we can investigate why it is occurring at your site - it may be due to an unexpected error / customer behaviour.