I am getting following error when I use drools *.drl file with in my EAR APP . I have following jars under app-inf/lib directory and other drools dependencies jars.. antlr-3.0ea8.jar; antlr-2.7.5H3.jar; stringtemplate-2.3b6.jar I am using weblogic 8.1 sp4. panic:ClassNotFoundException:org.antlr.stringtemplate.language.ChunkToke n and server dies,. Any help on this matter greatly appreciated. Thanks Parvesh