Hi, Russell. I have the same problem. I excluded <module name="org.apache.log4j" /> from deployement in jboss-deployment-structure.xml.
If I don't define any class in log4j.xml, then I get NullPointerException, when I write message. If I write class name in log4j, I have "ERROR Attempted to append to closed appender
['any class name'].
What's wrong?