Some notes about common pitfalls when trying to create or use existing JSF Portlets on AS 6.
AS6 is much more strict than previous releases, this has some consequences for applications that were running fine without being 100% spec compliant.
The webapp must be declared as a 2.5 version:
<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
TLDs (and most files associated to a schema, must strictly follow the schema. Ordering matters.(For instance, <description> usually starts before any other element.