It can happen that you get a traceback that notify you about connection issues while running Home Assistant. Eg.
ConnectionRefusedError: [Errno 111] Connection refused
The chance is very high that this is not a bug but an issue with the service/daemon itself. Check your network (DNS, DHCP, uplink, etc.) first and make sure that Home Assistant and the service are properly configured. Keep in mind that webservices can be down.