I have updated the code to not update the device if it doesn't exist... # Update energymeters (Wattcher) if ( len(Response["response"]["energymeters"]) != 0 ): try: en = Devices[self.en_id].sValue.split(";") en_0 = self.GetValue(Response["response"]["energymeters"][0], "po", "0") UpdateDevice(self ...