"Alarm State" is when the temperature is going outside of the programmed parameters. Not just too high of a temp, but also if the hot end temperature rises too fast. If the thermistor has been damaged, the extension wire has fatigued, or you have added an after-market thermistor or hot end, the thermistor/hot end will perform differently enough to signal that it is not operating as expected. This unexpected behavior will alert the machine and shut it down.
You may see an Alarm State screen if you print a material that requires a high temperature ...especially if the printer is heating up from a cold state. Cycling the power and starting the print job back up can resolve this because the temperature increase will be less dramatic than the first attempt since the hot end will still be heated up.