www.fleet.org has an A (IPv4) record (71.216.244.98) but a request to this address over port 80 did not succeed. Your web server must have at least one working IPv4 or IPv6 address.
Get http://www.fleet.org/.well-known/acme-challenge/letsdebug-test: EOF
Trace:
@0ms: Making a request to http://www.fleet.org/.well-known/acme-challenge/letsdebug-test (using initial IP 71.216.244.98)
@0ms: Dialing 71.216.244.98
@111ms: Experienced error: EOF
A test authorization for www.fleet.org to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
Fetching http://www.fleet.org/.well-known/acme-challenge/E7REOo5f1wtfWtKgYFOXFsGHmEtS5o6JxrYYiQhe-PE: Error getting validation data