My app works fine on JBoss AS 7.1. When I migrate to Wildfly 8.0.0 CR1, my JSP tags don't work as expected. My project is a EAR with WAR module.

When app starts, in the 1st access to page A, tag file is compiled and the page are rendered fine. But when I access another page (B in example), I got this error: org.apache.jasper.JasperException: java.lang.ClassCastException: org.apache.jsp.tag.web.default_tagx cannot be cast to org.apache.jsp.tag.web.default_tagx

If I restart Wildfly and try to access page B, works fine. But when I access page A, I got the same error.

My default.tagx is bellow:

<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" xmlns:html="http://www.w3.org/1999/xhtml" version="2.2">
<jsp:output doctype-root-element="HTML" doctype-system="about:legacy-compat" omit-xml-declaration="yes" />
some code
<jsp:doBody />
more code
</jsp:root>

And the pages are somethink like this:

<tags:default xmlns:tags="urn:jsptagdir:/WEB-INF/tags" xmlns:jsp="http://java.sun.com/JSP/Page" xmlns:html="http://www.w3.org/1999/xhtml">
<jsp:output omit-xml-declaration="yes" />
my code here
</tags:default>

I was created a new empty project with two pages and one tagfile. The error don't occurs. But when I add CDI capabilities, the error occurs. There are something in CDI that confuses Jastow?

As discussed here: https://community.jboss.org/message/850730