The cause is wrong version of JSF in the application server which is not compatible with RichFaces used in the example.
Trimmed console output:
10:06:14,790 WARN [org.ajax4jsf.webapp.BaseXMLFilter] This version of RichFaces implementation compatible for JSF1.2, but running under JSF2.0
The wrong version of JSF also affects Excel example. (see linked issue)