If your Arrow/Arrow+ is having issues, you can try the firmware recovery procedure using the latest Paralinx Manager here.
1. Power on your device in safe mode. To do this on the transmitter (Tx), hold the small button near the lights, then plug in the USB power through your computer (let go shortly after plugging in). On the receiver (Rx), hold the small button, plug in the barrel power, let go, then connect to the computer through USB.
2. Open Paralinx Manager and select the appropriate device when prompted.
3. Go to "Upgrade", click "Load from Web". Once loaded, click "Advanced Options".
4. Select Radio 1 and Radio 2 and click "Start Upgrade". Let the upgrade finish. Try upgrading the radios separately if upgrading together has issues.