Mattermost fails to connect after changing port


I have a Mattermost installation running on AWS. It works with a subdomain I created on my personal domain, but I am moving it to its own dedicated domain.

What I’ve done:

  • I’ve added the correct DNS record and it has propagated. I can verify by connecting to it on a separate service port, as well as connecting on port 80.
  • Checked AWS inbound rules to accept connections on 80 & 443.
  • Updated ufw rules.
  • Checked that the ports are open with netstat
  • Connected to it locally using various procedures found here

When I change the port from 80 to 443, it fails to connect. No errors in console or the logs, so I’m out of ideas. I am not using a proxy. I have Apache installed as a separate web process (not a proxy), and ports 80 and 443 are not in use.

Could there be something I missed?


My SSL certificate & key files were having problems. I used the internal Let’s Encrypt feature and it started working.