I've attempted to install the 5.5 appliance twice and everything appears to work, all green lights everywhere and I'm able, from the vCO side, to add my vCenter. However, on the vCenter side, the vCO server never appears and if I go to administration > Orchestrator and edit the settings there and try to test my connection, it always fails.
And then so far every time I've restarted the vCO service, the main vCO web front end comes up as a 500 error. The components work, I can get to the config, launch the client, etc., but the main page has the server error.