java.lang.RuntimeException: cannot invoke getter

we are using drools 5.4.final. and below is the rule

rule "EnergyUsage data not empty"
dialect "java"
salience 100
no-loop
when
$httpResponse : HttpResponse(
(((EnergyUsage)responseData).energyUsageDetail.billingGroup!=null && ((EnergyUsage)responseData).energyUsageDetail.billingGroup!=0) ||
((EnergyUsage)responseData).energyUsageDetail.capacityPLCs.size()>0 ||
((EnergyUsage)responseData).energyUsageDetail.networkServicePLCs.size()>0 ||
((EnergyUsage)responseData).energyUsageDetail.servicePoint!=null ||
((EnergyUsage)responseData).energyUsageDetail.historicalUsages.size() > 0
);

then
System.out.println("[EnergyUsage data not empty] rule has been fired...");
$httpResponse.setStatusCode(EisConstants.STATUS_OK);
$httpResponse.setErrorMessage("");
end

rule "EnergyUsage data empty"
dialect "java"
no-loop
when
$httpResponse : HttpResponse(
(((EnergyUsage)responseData).energyUsageDetail.billingGroup==null || ((EnergyUsage)responseData).energyUsageDetail.billingGroup==0) &&
((EnergyUsage)responseData).energyUsageDetail.capacityPLCs.size()==0 &&
((EnergyUsage)responseData).energyUsageDetail.networkServicePLCs.size()==0 &&
((EnergyUsage)responseData).energyUsageDetail.servicePoint==null &&
((EnergyUsage)responseData).energyUsageDetail.historicalUsages.size() == 0
);

then
System.out.println("[EnergyUsage data empty] rule has been fired...");
$httpResponse.setStatusCode(EisConstants.STATUS_OK);
$httpResponse.setErrorMessage("Data Screen Scrapping is empty for this account");
end

Here is log error:
-------------------------
java.lang.RuntimeException: cannot invoke getter: getEnergyUsageDetail [declr.class: com.bluestarenergy.core.eis.common.usage.EnergyUsage; act.class: com.bluestarenergy.core.eis.common.usage.EnergyUsage] (see trace)
at org.mvel2.optimizers.impl.refl.nodes.GetterAccessor.getValue(GetterAccessor.java:74)
at org.mvel2.ast.Union.getReducedValueAccelerated(Union.java:41)
at org.mvel2.ast.BinaryOperation.getReducedValueAccelerated(BinaryOperation.java:107)
at org.mvel2.ast.Or.getReducedValueAccelerated(Or.java:34)
at org.mvel2.ast.Or.getReducedValueAccelerated(Or.java:34)
at org.mvel2.ast.Or.getReducedValueAccelerated(Or.java:34)
at org.mvel2.ast.Or.getReducedValueAccelerated(Or.java:34)
at org.mvel2.MVELRuntime.execute(MVELRuntime.java:85)
at org.mvel2.compiler.CompiledExpression.getValue(CompiledExpression.java:123)
at org.mvel2.MVEL.executeExpression(MVEL.java:930)
at org.drools.rule.constraint.MvelConditionEvaluator.evaluate(MvelConditionEvaluator.java:70)
at org.drools.rule.constraint.MvelConditionEvaluator.evaluate(MvelConditionEvaluator.java:49)
at org.drools.rule.constraint.MvelConstraint.evaluate(MvelConstraint.java:167)
at org.drools.rule.constraint.MvelConstraint.isAllowed(MvelConstraint.java:124)
at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:137)
at org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:497)
at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:382)
at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:235)
at org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:240)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:337)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:298)
at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:888)
at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:847)
at org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:269)
at com.aepenergy.b2b.services.energyusage.UsageRulesServiceImpl.ruleCompliance(UsageRulesServiceImpl.java:19)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:90)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at $Proxy161.ruleCompliance(Unknown Source)
at com.aepenergy.b2b.services.energyusage.EnergyUsageCommunicationServiceImpl.processRequestEnergyUsageHttp(EnergyUsageCommunicationServiceImpl.java:52)