ActiveMQ, starting from version 5.8 has changed the names of some MBEANs used by Hermes plugin.
The code in the files
https://github.com/paoloantinori/HermesJMS/blob/fix_activemq58/src/java/hermes/ext/activemq/ActiveMQAdmin.java
https://github.com/paoloantinori/HermesJMS/blob/fix_activemq58/src/java/hermes/ext/activemq/ActiveMQAdminFactory.java
fixes the problem.
You can build it yourself or use the .jar I have already built:
https://github.com/paoloantinori/HermesJMS/blob/fix_activemq58/activemq_fix_dist/hermes-activemq.jar
Just copy the updated .jar over the old one that you can find in:
HERMES_INSTALLATION_FOLDER/lib/ext/
Based on these links:
http://stackoverflow.com/questions/16584244/how-can-one-make-hermesjms-adn-activemqbrowser-work-withe-latest-apache-activemq/16597888#16597888
http://activemq.apache.org/58-migration-guide.html
http://stackoverflow.com/questions/15837853/accessing-apache-activemq-via-jmx-throws-exception