When the "drools.agent.newInstance" property is set to false, the client
application which uses the KnowledgeAgent to recognize changes/ updates
performed in KnowledgeBase throws an exception. It is thrown after changing a
temporal rule and building the package:

Exception in thread "main" org.drools.RuntimeDroolsException: Unexpected
exception executing action
org.drools.rule.SlidingTimeWindow$BehaviorExpireWMAction@5e53bbfa
at
org.drools.common.AbstractWorkingMemory.executeQueuedActions(AbstractWorkingMemory.java:1001)
at
org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:734)
at
org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:701)
at
org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:218)
at com.sample.ExecutarAgente.main(ExecutarAgente.java:62)
Caused by: java.lang.NullPointerException
at org.drools.rule.SlidingTimeWindow.isExpired(SlidingTimeWindow.java:192)
at org.drools.rule.SlidingTimeWindow.expireTuples(SlidingTimeWindow.java:161)

*We are creating a test case to reproduce this bug.