JBoss ON Restart/Start Operation Failure when running JBoss A-MQ as Windows service

Issue

• On attempting to restart or start our AMQ broker from JON the operation fails with the following message:

java.lang.Exception: Start failed with error code null:
start.bat: Ignoring predefined value for KARAF_HOME

    at org.rhq.core.pc.operation.OperationInvocation.run(OperationInvocation.java:278)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
}

• JBoss ON Restart/Start Operation Failure when running JBoss A-MQ as Windows service
• The Stop operation works correctly (and the Restart option seems to stop the service but not bring it back up).