When grails packages the war it places hibernate.cfg.xml under WEB-INF/classes/hibernate. Hibernate expects to find hibernate.cfg.xml in the classpath and doesn't see it. Thus, grails does not detect my Java domain classes. If I copy the hibernate.cfg.xml to WEB-INF/classes, then it works. Either grails should place the hibernate.cfg.xml in WEB-INF/classes, or tell Hibernate where to find it. This issue started life on the mailing list: http://www.nabble.com/MissingMethodException-on-GORM-dynamic-methods-for-Java-domain-classes-tf4926322.html