If you are using JBoss AS 4.0.5.GA myfaces is installed into the AS so isn't needed in WEB-INF/lib.
How did you install JBoss?
I am using jboss-4.2.0.CR1 , I just donwload and unziped it on my file system. I am running it using JDK 5 on MacOsX.
Do you have some idea about what does this errors means?
JBoss 4.2 comes with the RI. Follow the instructions in the manual to use the RI not myfaces
Or get the latest version from CVS. Norman's been working on updating Seam and all the examples to run in JBoss 4.2.x, I'm not sure if seam-gen has been updated yet but you might be lucky, otherwise it won't be long.
Thank you Guys,
I will try both solutions.
No -seam-gen will get updated today.