Failing to navigate to plugin registration page after deploying vApp

Hi, we’ve been using Serengeti .8 for a bit and today found and wanted to talk a look at the new Big Data Extensions Beta package.  After I deploy the OVA, the management server starts up and I can access it (console/ssh) just fine, but when I hit the web service to register the plugin, I’m getting and SSL protocol error.

The URL (examples) I’m hitting per the documentation are https://servername.domain:8080/plugin   or https://10.20.30.40:8080/plugin   I see from the process list that Jetty/Java is handling port 8080, and when I hit the same URL without https, I see an apache/tomcat 404 page…?

Not sure exactly where to go next to troubleshoot the plugin registration.