Install latest on Ubuntu 16.04 - White screen on port 80. Admin on port 8080 works

I’ve installed on Ubuntu 16.0.4 using the community edition .zip. When I access http://host:8080 I get an admin screen. I’m able to log onto the server admin page.
When I access http://host:80, I get a blank screen with no prompt to log on.

I don’t see an error in the /opt/metasfresh/log/metafrXXXX.log file that occurs when I attempt this access.
I do see this error repeatedly WARN 13622 — [http-nio-8080-exec-6] i.s.m.p.AbstractSerializableParameter : Illegal DefaultValue 500 for parameter type integer