A “Sensor Error” message appears when the sensor is temporarily unable to provide a glucose reading, for instance, during intense exercise. With the FreeStyle Libre 2 system, simply wait the duration specified on the screen and scan again.
For optimal sensor performance, carefully follow the guidance for sensor application on the sensor’s label. You can find additional resources, such as helpful tips and tutorial videos for sensor application and care, on the Support Overview page.
For full details please refer to the FreeStyle Libre 2 User's Manual which is available in English and French