IllegalStateException: unread block data error is thrown while managing tasks in JBoss BRMS 5.3.1

Issue

• The following errors are raised while managing some processes (such as trying to getTask, starting a process, getting a list of taks, etc):
  What could be the root cause behind these errors?

2014-03-26 16:15:40,056 ERROR [org.jbpm.task.service.hornetq.HornetQTaskClientConnector] (Thread-366) Client Exception with class class org.jbpm.task.service.hornetq.HornetQTaskClientConnector$1 using port 5153
java.lang.IllegalStateException: unread block data
    at java.io.ObjectInputStream$BlockDataInputStream.setBlockDataMode(ObjectInputStream.java:2399)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1359)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1969)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1893)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1775)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1327)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:349)
    at org.jbpm.task.service.hornetq.HornetQTaskClientConnector.readMessage(HornetQTaskClientConnector.java:160)
    at org.jbpm.task.service.hornetq.HornetQTaskClientConnector.access$300(HornetQTaskClientConnector.java:45)
    at org.jbpm.task.service.hornetq.HornetQTaskClientConnector$1.run(HornetQTaskClientConnector.java:122)
    at java.lang.Thread.run(Thread.java:662)

2014-03-26 16:15:50,050 ERROR [com.sample.test.services.HumanTaskServiceImpl] (WorkManager(2)-76) Exception occured whilst getting the task details for task - 25  from external BPM Engine
java.lang.RuntimeException: Timeout : unable to retrieve Task
    at org.jbpm.task.service.responsehandlers.BlockingGetTaskResponseHandler.getTask(BlockingGetTaskResponseHandler.java:41)    
...