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/5s4u3WKnpgiZo8m9yrqyI_nTfvKz9juoykTOeCNOd4U: Timeout during connect (likely firewall problem)