In many cases, the detection sensor is not working properly, check this first. In some cases, people want to make the next bottle too quickly. The water has to warm up first. This can be seen by the blinking milk bottle in the upper left corner. When it stops flashing, the water is at the correct temperature and a new bottle can be made. After the bottle has been made, the light will blink again because the water is heating up and the next bottle cannot be made immediately. It may also be the case that you have not yet removed your bottle. You cannot make two bottles without having removed the bottle first.