Clean the downword sensor lens, if error persists
Use the Assistant to recalibrate the sensors, if error persists
Re-Flash the Drones firmware, if error persists
Replace the sensor.
(The recal should clear the error.)
The only SD card that has ever failed me was the free one DJI sent to me for providing feedback. A guy I know replaces his SD cards every year. Not sure what tragedy he experienced to cause him to do this but it was enough for him. Replace the SD...