title: Why isn't certbot writing the verification file?
body: <p>I am trying to install a certificate using certbot on Ubuntu Xenial by using the below command:</p>
  <pre><code>sudo certbot run -a webroot -i apache -w /var/www/mydomain/public/.well-known/acme-challenge/ -d &quot;example.com&quot;
  </code></pre>
  <p>I get a challenge failed error with the following notes:</p>
  <pre><code>Domain: mydomain.com
     Type:   unauthorized
     Detail: Invalid response from
     http://example.com/.well-known/acme-challenge/lvJ9RbuDyoPn4NXnxPpjOYpsGHZb6ZYdDoBWW-6JC1k
  </code></pre>
  <p>I created the /.well-known/acme-challenge myself thinking this might help, but it didn't.  I tried putting a file into the acme-challenge directory and browsed to it through Chrome and this worked without an issue. Therefore, I know the Apache host is setup correctly.</p>
  <p>I'm now at a loss of what to try.</p>