vSphere Integrated Containers Management Portal is controlled by admiral service running on VIC appliance. So this issue occurs when the admiral service is unable to start because of exception "publicUri should be a non empty absolute URI". The public URI is the FQDN that is configured at the time of VIC appliance. So please verify if any underscore(s) are part of the FQDN such as www.my_example.com. Having an underscore in FQDN is not supported by admiral service hence the service fails to start and gives out an exception.