Please post the complete stacktrace and the contents of your jboss-deployment-structure.xml
Sorry it was code issue. I was migrating an application from JBoss 4 to Wildfly 9.
There is a code where explicitly setting context classloader to parent classloaders
ClassLoader cl = TestXXX.class.getClassLoader().getParent().getParent().getParent().getParent();
It worked when i removed this because the current class loader in wildfly is: org.jboss.modules.ModuleClassLoader and most of the dependent classes (including com.sun.el.ExpressionFactoryImpl) are loaded from module dependency.