I realize that post is about a 5.0 beta, but from what I recall the issue with web console on 4.2.x is similar and the fix is similar.
Thanks for your reply.
I have that problem with JBoss 5.0.0.CR2 and 4.2.2.GA also.
provided solution didn't work :(
any other clue
The web console works for me 5.0.0.CR2. I am using JDK 6u7 and Firefox.
For 4.2.2, you will have to debug it yourself. Open the Java console within your browser first, then access the web console, the Java console should tell you what the errors are (usually a missing class).
oh ok thanks Petere :)