[rules-users] Trouble upgrading to Drool 4.0

Hi, I have been using JBoss Drool 3.06 for a few months, and now I want to upgrade it to 4.0 to take advantage of some new features. So I downloaded the JBoss Rules 4.0.0.MR3 Binaries, then drop 4 core drool jar files to my project lib drools-core.jar drools-compiler.jar drools-jsr94.jar drools-decisiontables.jar Then I rebuilt my project, changed a few Drool java code to adapt with 4.0, then Run. I got the following error message: java.lang.NoClassDefFoundError: org/mvel/intergration/VaribaleResolverFactory. Could anyone please let me know if I am mising anything? Thank you! PS: My Java drool was working fine with 3.0.6 Tim