If status of Agent in IBM uDeploy UI is Error then click on the icon. You may find following error:
IBM UrbanCode Deploy: The agent could not connect to the server or relay using HTTP.
To remove it, Set External URL with IP address or DNS name as shown below in System Settings:
Go to VM where agent is installed and restart it with ./agent stop and ./agent start command
Once you restart the agent, verify on IBM Urban code Deploy UI, status of Agent will be online