If you get either of these errors:
Failed to create a new SAX parser
[XMLLoginConfigImpl] End loadConfig, failed to load config: login-config.xml
org.jboss.security.auth.login.ParseException: Encountered "
Chances are this is a jar compatibility issue. Take your war file and remove
candidate jar files that are in your war, but that JBoss already has on its classpath, such as: