[rules-users] java.lang.LinkageError, but only sometimes

Dear list, We have an application (A) deployed on JBoss 7.1.1 accepting commands (CQRS, but only C and Q :) ). A console application (B) is sending a large volume of commands to create entities in A. Entities in A are validated by Drools (plain drl files, configured in spring using drools-spring). Most of the time this works just fine. But sometimes, we get the following exception: java.lang.LinkageError: loader (instance of org/drools/rule/JavaDialectRuntimeData$PackageClassLoader): attempted duplicate class definition for name: "a/b/c/Rule_person_unique___name_656ee3db19d34e689d95e2d6b2be67b6" at java.lang.ClassLoader.defineClass1(Native Method) [rt.jar:1.6.0_30] at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631) [rt.jar:1.6.0_30] at java.lang.ClassLoader.defineClass(ClassLoader.java:615) [rt.jar:1.6.0_30] at org.drools.rule.JavaDialectRuntimeData$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_gg___unique___name_656ee3db19d34e689d95e2d6b2be67b6Eval0InvokerGenerated.evaluate(Unknown Source) at a.b.c.Rule_gg___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] Any idea where this is coming from or what's causing this. We are using: - JBoss 7.1.1 - drools 5.4.0.Final - jdk 1.6u30 - Windows 7 64 bit regards, Kenneth -- View this message in context: http://drools.46999.n3.nabble.com/java-lang-LinkageError-but-only-sometim... Sent from the Drools: User forum mailing list archive at Nabble.com.