seems to be regression from: https://issues.apache.org/activemq/browse/AMQ-2970 - but there is some mix up with the creation of an admin connection context. having the BrokerView do the right thing works for the moment... but this needs some more eyes, test shows the issue when context is missing
activemq/trunk/activemq-core/src/main/java/org/apache/activemq/broker/jmx/BrokerView.java