One tyre not detected

All my 4 tyres have been detected and working until recently, when the front right sensor displayed the message ERR. I tried to do the following but the message remained:. 1. Replaced the battery if the sensor 2. Disabled and re-enabled the sensor 3. Swapped the sensor with the rear right tyre 4. Swapped the sensor with the front left tyre 5. Inflated the front right tyre to the correct pressure level What could be wrong?