Hi, Initially I am using jboss-drool 5.0.1 version in our project and I updated to jboss-drools 5.4.0 version in our project but I am getting linkage errors as mentioned below. java.lang.LinkageError: loader (instance of org/drools/rule/JavaDialectRuntimeData$PackageClassLoader): attempted duplicate class definition for name: "com/ds/rule/vm/fvm/ruleengine/Rule_Product_has_minimum_number_of_valid_quotes_5263d589f8864649bbb734bada7a54ed" at java.lang.ClassLoader.defineClass1(Native Method) [rt.jar:1.6.0_30] at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631) [rt.jar:1.6.0_30] at java.lang.ClassLoader.defineClass(ClassLoader.java:615) [rt.jar:1.6.0_30] at org.drools.rule.JavaDialectRuntimeData$PackageClassLoader.fastFindClass(JavaDialectRuntimeData.java:615) [drools-core-5.4.0.Final.jar:5.4.0.Final] at org.drools.util.CompositeClassLoader$CachingLoader.load(CompositeClassLoader.java:254) [knowledge-api-5.4.0.Final.jar:5.4.0.Final] at org.drools.util.CompositeClassLoader$CachingLoader.load(CompositeClassLoader.java:237) [knowledge-api-5.4.0.Final.jar:5.4.0.Final] at org.drools.util.CompositeClassLoader.loadClass(CompositeClassLoader.java:88) [knowledge-api-5.4.0.Final.jar:5.4.0.Final] at java.lang.ClassLoader.loadClass(ClassLoader.java:295) [rt.jar:1.6.0_30] at java.lang.ClassLoader.loadClass(ClassLoader.java:247) [rt.jar:1.6.0_30] at a.b.c.Rule_person___unique___name_656ee3db19d34e689d95e2d6b2be67b6Eval0InvokerGenerated.evaluate(Unknown Source) at a.b.c.Rule_person___unique___name_656ee3db19d34e689d95e2d6b2be67b6Eval0Invoker.evaluate(Unknown Source) at org.drools.rule.EvalCondition.isAllowed(EvalCondition.java:114) [drools-core-5.4.0.Final.jar:5.4.0.Final] And each time I ran the project I am getting same error but on different rules. Could you please help me out how to solve this issue? with regards, k.chaitanya. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users