To fix a RADIUS server not responding, check the network connection to ensure it is properly configured. Then check the RADIUS server logs to identify any errors or warnings that could be causing the issue. If necessary, restart the RADIUS server service and test its functionality. If the issue persists, try reinstalling the RADIUS server software and reconfiguring settings. If all else fails, contact your IT support team for assistance.
Follow this guide for full guide on how to solve this error by not responding