Manage Jenkins page displays this Error: “The connection to Gerrit is down! Check your settings and the Gerrit server”

Issue: When the Gerrit server shuts down suddenly, the Gerrit trigger loses connectivity and stops working. The only way to get it restarted is to restart the whole Jenkins instance. Attempting to restart the gerrit trigger in Jenkins by using the Control box does not work. Firebug POSTs to this: http://jenkins:8210/descriptorByName/com.sonyericsson.hudson.plugins.gerrit.trigger.GerritManagement/startConnection

and never receives a response from the server.

Jenkins log files doesn't provide more information.