I see something like the following line in log:
WARN: Recived 404 Status Code "Not Found" from server [IP:Port] while fetching "/tor/keys/fp/[hash refrence here]"
Two very intresting things come up on investigation:
The involved IP is not a Tor node according to atlas, and i know it isn't a bridge node.
To my understanding Tor isn't supposed to be an HTTP server, but rather a SOCKS server, so it begs me to reason why tor would be making an HTTP request for some sort of key in the first place.
Really makes me wonder whats going on.