Instructions for installing Tyk on Ubuntu 16.04 results in broken portal

Now I have, thanks for the pointer (would be good to put a link to that in the installation instructions). I get stuck at Step 6 - trying to set the portal domain from the Dashboard results in a “There was a problem updating your CNAME, please contact support” dialog. Manually replacing the IP-based URL that Open Your Portal is trying to go to with the domain name-based URL is still resulting in a Not Found.