Jboss Rules and Weblogic
Weblogic 8.1.0-8.1.5 i think uses antlr old version and hence when you use Jboss Rules 3.0.5 with Weblogic it will give Antlr Panic Exception message of not able to load the class ChunkToken.
The work around is to have antlr 2.7.6 jar file in PRE-CLASSPATH of Weblogic. This way the application works fine. If you are intrested more in this Weblogic Bug it can be found in
An Antlr conflict exists between Hibernate 3 or Jboss loading of antlr jar and WebLogic Server.
Workaround or Solution:
Place Antlr2.7.5.jar before weblogic.jar in your CLASSPATH.