Ninebot Max Error Code 18
"Wheel Hub Motor Hall is abnormal , Please check the Motor, Control Board & related connections"
Error 18 is thrown when the scooter detects an abnormal reading from the hall sensors in the motor.
This can be due to an unplugged cable, or a blown sensor/resistor.
The best case scenario would be that the 5 pin motor cable has come unplugged or was severed somehow.
Check the cable and visually inspect that it is still plugged in firmly and is free from any fraying.
After that, a new motor may be needed or the sensors may need to be repaired.