This error means that either the thermistor is not connected, or there is a short. If this is for a cnc, without a thermistor, then I believe you need to have a 100k resistor where the thermistor would go to fool the firmware. As for the blue screen, this may just be due to not configuring it correctly in the firmware. In the configuration file of Marlin, there is a subsection where you can select which LCD you are using. You will have to enable to correct LCD.
Also appears we have the same username. This might get confusing! I’ll change it.