I wanted to add a new network segment to deploy a new domain in my lab.  When I went to add a new interface to the edge, no port groups were showing up. 

I was running version 5.5.0 so I upgraded to version 5.5.2, but still no port groups were showing up.  I saw that there was an upgrade available so I clicked Actions, Upgrade.  The Edge redeployed and then the port groups showed up.  

I had another Edge with the same problem, but this time instead of upgrading I just clicked Actions, Redeploy Edge and after it redeployed I was able to select a Port Group.