I have a simple web application (one jsp and one servlet) file that I've copied into jboss-4.0.2/server/default/deploy folder and it has successfully hot deployed as I can access the jsp page. However, when I invoke the servlet, I am getting a java.lan.NoClassDefFoundError. I suspect that the jars under the WEB-INF/lib directory within the war is not being picked up. The structure of my war is: META-INF --> MANIFEST.MF WEB-INF --> classes --> ...*.classes --> lib --> jcommon-1.0.16.jar jfreechart-1.0.13.jar servlet-api.jar index.jsp Anybody else have classloading issues in JBoss 4? Many thanks.