This is the top of a facelets page:

Code:

ui:composition xmlns:ui="http://java.sun.com/jsf/facelets"    xmlns:h="http://java.sun.com/jsf/html"    xmlns:f="http://java.sun.com/jsf/core"    xmlns:ice="http://www.icesoft.com/icefaces/component"    template="/templates/main.xhtml" >

All of the xmls:xx are flagged as 'unknown attribute (xx)' where xx is ui, h, f, ice, etc. When I run my app it works just fine.

Why would I be getting these validation errors?

I found my own answer. I went looking in the dtd and found that IceFaces specifies the ui URI as http://java.sun.com/jsf/facelet. No 's' at the end. I wonder if this isn't a bug on their part.

Ok. That wasn't it. The above does make the validation errors go away, but then the page doesn't work correctly. It doesn't see the main.xhtml template so other things break. I just put the 's' back on to facelets in the URI and now the page works fine again, but the validation markers are back.

This is enough to drive someone insane!