Hi there, we tried to use drools jars from an url: 1. define an URLClassLoader with all the urls of the necessary drools jars in the search path. 2. initialize a KnowledgeBaseConfiguration with that class loader KnowledgeBaseConfiguration knowledgeBaseCfg = KnowledgeBaseFactory .newKnowledgeBaseConfiguration(null, dcURLClassLoader); 3. initialize a KnowledgeBase with that configuration KnowledgeBase kbase = KnowledgeBaseFactory .newKnowledgeBase(knowledgeBaseCfg); 4. initialize a KnowledgeBuilderConfiguration with that class loader KnowledgeBuilderConfiguration knowledgeBuilderCfg = KnowledgeBuilderFactory .newKnowledgeBuilderConfiguration(null, dcURLClassLoader); 5. initalize a knowledge builder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(kbase, knowledgeBuilderCfg); 6. adding a knowledge resource to that builder results in a org.drools.RuntimeDroolsException "Unable to load dialect org.drools.rule.builder.dialect.java.JavaDialectConfiguration:java" if the drools jars are not in the start class path. Did we something wrong or uses drools while adding ressources a classloader different from that given in the configuration?. Thanks in advance Ulrich -- View this message in context: http://drools.46999.n3.nabble.com/loading-rules-and-drools-classes-via-UR... Sent from the Drools: User forum mailing list archive at Nabble.com.