title: Problem binding to port 80: Could not bind to IPv4 or IPv6
body: <p>I have 2 projects running on different ports - 80 and 8005 on the same server. These ports point to example1.com and example2.com respectively. I installed SSL certificate for example1.com using <a href="https://tecadmin.net/install-lets-encrypt-create-ssl-ubuntu/" rel="nofollow noreferrer">https://tecadmin.net/install-lets-encrypt-create-ssl-ubuntu/</a> and it worked. However when I tried for example2.com, I got this error - <code>Problem binding to port 80: Could not bind to IPv4 or IPv6.</code></p>
  
  <p>I am guessing it needs example2.com to be port 80, is there a workaround this? How can I install a SSL certificate for example2.com?</p>