I tried that but the problem still persist. The problem only happens if I install JBossWS-CXF and create a jbossws-cxf.xml file under WEB-INF directory.
I set log level to TRACE and I saw these lines seems to have caused the issue:
08:22:38,986 TRACE [org.jboss.modules] (http--127.0.0.1-8083-1) Finding class javax.servlet.ServletException from Module "org.jboss.ws.jaxws-client:main" from local module loader @13f7281 (roots: /Users/stephen/Programs/jboss-as-7.1.1.Final/modules)
08:22:38,987 TRACE [org.jboss.modules] (http--127.0.0.1-8083-1) Class javax.servlet.ServletException not found from Module "org.jboss.ws.jaxws-client:main" from local module loader @13f7281 (roots: /Users/stephen/Programs/jboss-as-7.1.1.Final/modules)
Any clues as to what is the issue? I attached the complete log file.