I am encountering the following error when trying to invoke a web service. using Jboss 4.2.2 and jbossws-native-2.0.1.GA webservices. "Class javax/xml/rpc/ParameterMode violates loader constraints" Has anyone got an idea? thanks, org.apache.jasper.JasperException: javax.servlet.ServletException: java.lang.LinkageError: Class javax/xml/rpc/ParameterMode violates loader constraints org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:521) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:397) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:336) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265) javax.servlet.http.HttpServlet.service(HttpServlet.java:803) org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) root cause javax.servlet.ServletException: java.lang.LinkageError: Class javax/xml/rpc/ParameterMode violates loader constraints org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:850) org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:779) org.apache.jsp.views.jbossws_jsp._jspService(jbossws_jsp.java:183) org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) javax.servlet.http.HttpServlet.service(HttpServlet.java:803) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:336) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265) javax.servlet.http.HttpServlet.service(HttpServlet.java:803) org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) root cause java.lang.LinkageError: Class javax/xml/rpc/ParameterMode violates loader constraints java.lang.ClassLoader.defineClass1(Native Method) java.lang.ClassLoader.defineClass(ClassLoader.java:620) java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124) org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:1814) org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:872) org.jboss.web.tomcat.service.WebAppClassLoader.findClass(WebAppClassLoader.java:139) org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1325) org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204) java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319) java.lang.Class.forName0(Native Method) java.lang.Class.forName(Class.java:164) $Proxy255.(Unknown Source) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4155079#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...