Okay, found the issue. I used maven to build my war, and I built the dependencies that pulled the jars from maven central. It appears those are incompatible with the Seam setup. What I had from maven: commons-jci-core-1.0.jar commons-jci-janino-1.0.jar drools-compiler-3.0.5.jar drools-core-3.0.5.jar If I install into maven the jars from seam 1.2.1: commons-jci-core-1.0-406301.jar commons-jci-janino-2.4.3.jar drools-compiler-3.0.5.jar drools-core-3.0.5.jar It works. Sorry for the rabbit trail. Hopefully at one point all the seam jars will be hosted on maven with a seam archetype. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4057072#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...