JBoss ON install fails with "The installer will now exit due to previous errors: java.lang.Exception: Cannot obtain client connection to the RHQ app server!!"

Issue

• JBoss ON install fails with "Exit value: 2"
• Install of JBoss ON results in "Could not connect to remote://127.0.0.1:9999. The connection timed out" error
• JBoss ON install fails with "Cannot obtain client connection to the RHQ app server"

• Installer reports errors similar to:

  ERROR [org.rhq.enterprise.server.installer.Installer] The installer will now exit due to previous errors: java.lang.Exception: Cannot obtain client connection to the RHQ app server!!
  ...
  Caused by: java.io.IOException: java.net.ConnectException: JBAS012144: Could not connect to remote://127.0.0.1:9999. The connection timed out
  ...
  Caused by: java.net.ConnectException: JBAS012144: Could not connect to remote://127.0.0.1:9999. The connection timed out
  ...
  

• Install process returns error similar to:

  ... ERROR [org.rhq.server.control.command.Install] An error occurred while starting the RHQ server: Process exited with an error: 2 (Exit value: 2)
  Trying to stop the RHQ Server...
  RHQ Server (pid=23923) is stopping...
  RHQ Server has stopped.
  Stopping RHQ storage node...
  RHQ storage node (pid=23772) is stopping...
  RHQ storage node has stopped
  ... ERROR [org.rhq.server.control.RHQControl] Process exited with an error: 2 (Exit value: 2)