On deploying a JSF 2.2 / Primefaces 5 application on Jetty 9, I got the following error:
java.lang.IllegalStateException: Could not find backup for factory javax.faces.context.FacesContextFactory.
The issue seems linked to Jetty, since I could not reproduce the issue on Tomcat 8.
web.xml, add the following block:
<listener> <listener-class>com.sun.faces.config.ConfigureListener</listener-class> </listener>