Hi, I am getting an error at inconsistent intervals while executing one scheduled task, which uses rules, in Websphere AS. Below is the error trace, [9/22/11 8:57:59:316 CDT] 0000004d SystemErr R Caused by: java.lang.ClassNotFoundException: autoclassification.Rule_10___10_Auto_Classification_0DefaultConsequenceInvoker at java.lang.Class.forNameImpl(Native Method) at java.lang.Class.forName(Class.java:163) at org.drools.rule.DroolsCompositeClassLoader.loadClass(DroolsCompositeClassLoader.java:91) at java.lang.ClassLoader.loadClass(ClassLoader.java:573) at org.drools.rule.JavaDialectRuntimeData.wire(JavaDialectRuntimeData.java:312) at org.drools.rule.JavaDialectRuntimeData.reload(JavaDialectRuntimeData.java:379) at org.drools.rule.JavaDialectRuntimeData.onBeforeExecute(JavaDialectRuntimeData.java:139) at org.drools.rule.DialectRuntimeRegistry.onBeforeExecute(DialectRuntimeRegistry.java:132) at org.drools.compiler.PackageBuilder.reloadAll(PackageBuilder.java:683) at org.drools.compiler.PackageBuilder.addPackage(PackageBuilder.java:641) at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:266) at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:458) at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:28) at com.dell.compliance.middleware.ruleengine.RuleEngine.fire(RuleEngine.java:43) The rules are: package autoclassification; import com.dell.compliance.middleware.business.Part; import java.util.Map; function boolean like(String masterData, String transData) { boolean result = false; if (masterData == null) { return result; } if (transData != null && transData.trim().length() > 0) { if (transData.trim().startsWith('%') && !transData.trim().endsWith('%')) { result = masterData.endsWith(removeChar(transData)); } else if (!transData.trim().startsWith('%') && transData.trim().endsWith('%')) { result = masterData.startsWith(removeChar(transData)); } else if (transData.trim().startsWith('%') && transData.trim().endsWith('%')) { result = masterData.contains(removeChar(transData)); } else { result = masterData.equals(transData); } } return result; } function String removeChar(String transData) { String str = transData.replaceAll('%', ''); return str; } function boolean validateTechAttribute(Map taMap, String attrNames, String attrVals) { boolean result = false; if (attrNames == null || attrVals == null) { return true; } if(taMap == null){ return false; } String[] attrs = attrNames.split('[|]'); String[] values = attrVals.split('[|]'); String attr = null; String value = null; String attrVal = null; for (int i = 0; i &lt; attrs.length; i++) { attr = attrs[i] != null ? attrs[i].trim().toUpperCase() : ''; value = values[i] != null ? values[i].trim().toUpperCase() : ''; if (taMap.containsKey(attr)) { attrVal = (String) taMap.get(attr); result = like(attrVal, value); if(result==false){ return result; } } else { return false; } } return result; } rule '2 - 2_Auto Classification' when part : Part(eval (like(partType,'Hard Drive (NBK)')) , eval (like(partClass,'Drive,Hard')) , eval (validateTechAttribute(techAttrList,'Placement|Encrypted Drive','Internal|No'))) then part.setPartDesc('HARD DRIVE-INTERNAL'); update(part); drools.getWorkingMemory().clearAgenda(); end rule '3 - 3_Auto Classification' when part : Part(eval (like(partType,'Hard Drive (NBK)')) , eval (like(partClass,'Drive,Hard')) , eval (validateTechAttribute(techAttrList,'Placement|Encrypted Drive','Internal|Yes'))) then part.setPartDesc('HARD DRIVE-INTERNAL-ENCRYPTED'); update(part); drools.getWorkingMemory().clearAgenda(); end -- -- -- rule '9 - 9_Auto Classification' when part : Part(eval (like(partType,'Card,Network')) , eval (like(partClass,'CARD,NETWORK')) , eval (validateTechAttribute(techAttrList,'Wireless |SWIncludesEncryption','no|Yes'))) then part.setPartDesc('POPULATED PCB-NETWORK-ADAPTER-ENCRYPTED'); update(part); drools.getWorkingMemory().clearAgenda(); end rule '10 - 10_Auto Classification' when part : Part(eval (like(partType,'Card,Wireless')) , eval (like(partClass,'CARD,NETWORK')) , eval (validateTechAttribute(techAttrList,'Wireless |SWIncludesEncryption','yes|Yes'))) then part.setPartDesc('POPULATED PCB-NETWORK WIRELESS WLAN'); update(part); drools.getWorkingMemory().clearAgenda(); end And the Code loading rules is in RuleEngine.java as: public void fire(byte[] rules, Object obj) { final KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); // this will parse and compile in one step kbuilder.add(ResourceFactory.newByteArrayResource(rules),ResourceType.DRL); // Check the builder for errors if (kbuilder.hasErrors()) { System.out.println(kbuilder.getErrors().toString()); throw new RuntimeException("Unable to compile drl."); } // get the compiled packages (which are serializable) final Collection<KnowledgePackage> pkgs = kbuilder.getKnowledgePackages(); // add the packages to a knowledgebase (deploy the knowledge packages). final KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(); kbase.addKnowledgePackages(pkgs); final StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession(); ksession.addEventListener(new DebugAgendaEventListener()); ksession.addEventListener(new DebugWorkingMemoryEventListener()); // setup the audit logging //KnowledgeRuntimeLogger logger = KnowledgeRuntimeLoggerFactory.newFileLogger(ksession, "log/drools.log"); ksession.insert(obj); ksession.fireAllRules(); //logger.close(); ksession.dispose(); } We used Drools 5.1, Please help me resolve as soon as possible. Thanks & Regards Santhosh