If the base is detached, install the base back first.
Go to touchscreen > Maintain, observe the icon on the top right corner. Check if the door icon is changed to “closed” when the front door is closed. If the icon is changed, the machine should operate normally.
If the icon didn’t change, please check if the door magnet fell off.
If the magnet is still in place, open the back lid, take a magnet and place it over the sensor.