Classically,  a System error can be defined as some sort of instruction given to the operating system which is undefined to the system or it is violating the procedures existing in it.  A System error in an ATM can be defined along the same line. Most of the errors are related to preserving the security of the customer. In modern ATMs a lot of sensors like- Door Lock Sensors, Floor Sensors, Cam sensors, Intrusion sensors, Shock sensors, and sensors that can detect fraud exists. All these sensors are built-in in into an ATM machine to protect against undesirable entry, or attacks.