When I want to use jsf-api.jar and jsf-impl.jar instead of myfaces-api-1.1.5.jar and myfaces-imp-1.1.5.jar I have error: Caused by: java.lang.LinkageError: loader constraint violation: when resolving method "javax.faces.application.Application.getExpressionFactory()Ljavax/el/ExpressionFactory;" the class loader (instance of org/jboss/web/tomcat/service/WebAppClassLoader) of the current class, com/sun/facelets/compiler/Compiler, and the class loader (instance of org/jboss/mx/loading/UnifiedClassLoader3) for resolved class, javax/faces/application/Application, have different Class objects for the type javax/el/ExpressionFactory used in the signature View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4111641#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...