We are currently using HornetQ 2.2.5 and would like to upgrade to 2.2.18 to fix a number of bugs. However, I tried updating the client-side java libraries and now the client (2.2.18 libs) cannot connect to the existing HornetQ server (2.2.5). Does the HornetQ server side need to be upgraded first? I thought that with v2.2.0 things were backward compatible... Here is the error I am getting on the client side:

Subscriber error: Problem connecting to JMS server: problem while getting Connection

com.xyz.MessagingException: problem while getting Connection

    at com.xyz.JMSSubscriber.setupConnection(JMSSubscriber.java:181)

    at com.xyz.JMSSubscriber.connectLoop(JMSSubscriber.java:108)

    at com.xyz.JMSSubscriber.access$0(JMSSubscriber.java:100)

    at com.xyz.JMSSubscriber$1.runSafe(JMSSubscriber.java:93)

    at com.xyz.SafeThread.run(SafeThread.java:42)

Caused by: javax.jms.JMSException: Failed to create session factory

    at org.hornetq.jms.client.HornetQConnectionFactory.createConnectionInternal(HornetQConnectionFactory.java:605)

    at org.hornetq.jms.client.HornetQConnectionFactory.createConnection(HornetQConnectionFactory.java:119)

    at org.hornetq.jms.client.HornetQConnectionFactory.createConnection(HornetQConnectionFactory.java:114)

    at COM.NextBus.avl.greyisland.ws.push.JMSSubscriber.setupConnection(JMSSubscriber.java:144)

    ... 4 more

Caused by: java.lang.NullPointerException

    at org.hornetq.core.client.impl.ServerLocatorImpl.removeFromConnecting(ServerLocatorImpl.java:687)

    at org.hornetq.core.client.impl.ServerLocatorImpl.createSessionFactory(ServerLocatorImpl.java:756)

    at org.hornetq.jms.client.HornetQConnectionFactory.createConnectionInternal(HornetQConnectionFactory.java:601)

    ... 7 more