JSF xmlns URI not registered in IntelliJ IDEA

Question

Here is the start of my JSF file:

Answer 1

I was having same issue with icefaces resources.
One way to fix this is to give the project (again, if you already did not) the IceFaces framework support (right click on project name).
In my case I was using 3.3.0, then I set download in the Add Framework Support form.
Intellij downloaded 3.1.0 and the IDE recognizes the resource immediately after. Later I set again the 3.3.0 version.
So, I think is enough to re download the framework again, and the resources will be downloaded in META-INF folder.

Regards.-