Finally I tried jdk1.5.0.
Seems to work but I'd prefer a final release rather than a RC...
Im just starting out here and Im getting the same error.
I have the same error message.
Is this error the source of the failure of an application deployment?
Well, using jdk1.5.0 was not so fine... Accessing the jmx-console does not work (because of version number of some classes, such as servlet).
Is jboss supposed to compile with jdk1.5.0 ? (Does not seem at first glance)
I had this error, too. I found the solution @ google for a different tool but the workaround also worked for JBoss.
I copied the directory "%JBOSS_HOME%\lib\endorsed" to "%JAVA_HOME%\jre\lib" after that it worked.
But now I have another error (see my current thread) :-(
To fix this just add the following to your start vm arguments in the debug configuration dialog