The Liberty server cannot load application modules where the application.xml deployment descriptor has a namespace value that does not match the defined version.
Application modules at version 1.4 must use the http://java.sun.com/xml/ns/j2ee namespace.
Application modules at version 5 or 6 must use the http://java.sun.com/xml/ns/javaee namespace.
Application modules at version 7 or later must use the http://xmlns.jcp.org/xml/ns/javaee namespace.