A test authorization for books.darkvirtue.com to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
156.96.60.101: Fetching http://books.darkvirtue.com/.well-known/acme-challenge/TwvhtwTulSRkkQNpS9NV_kQhMY9PaS3UDu0qaHQ_SYw: Timeout during connect (likely firewall problem)