If an error message saying "System UI has stopped." appears, particularly if attempting to access the Android Settings, please check to see if the tablet is locked.
If the tablet is locked in Student Mode, please unlock the device first, and then try accessing the Settings again. This message normally appears only when a user attempts to access the tablet's settings while the device is locked in Student Mode. The buttons may disappear for about a second or two and then return to the main screen as it was before.
If the error message appears even when the tablet is unlocked, please contact the support desk for further assistance.