"Sensor not connected or invalid data" with weather station GMX240

[trungvm]

When I used Smart Agriculture Xtreme with Weather Station GMX240, sometimes the response returned false in the reading sensor's data code and can't read data from it. I turn off the sensor and turn it on by "mySensor.ON/OFF" but it isn't working. when I restart libe power then it worked. So it still happens when using the example code.
Have any problem with it? It's a hardware problem or something I forgot when setup the weather station?