I realised that jboss-metadata jar was missing, after i downloaded jboss-metadata-1.0.0.Beta6.jar and copied under LIB, error has changed.
You don't have to download additional jars to have the AS functional. If you had to do that, then it might be a sign that you don't have a clean JBoss AS installation or a proper download.
Caused by: org.jboss.xb.binding.JBossXBRuntimeException: module-order not found as a child of jboss-app in unordered_sequence: module* security-role* jmx-name? loader-repository? unauthenticated-principal? security-domain? library-directory? version? {all descriptionGroup}?
What does your jboss-app.xml look like? Perhaps you haven't listed the xml elements in the right order (JBoss AS5 is strict when it comes to xml element ordering).