I have seen that error when there is an attempt to parse an xsd file, that is not a schema. The error is coming from the xerces layer so the question is one of getting hold of enough info to improve this error. What was the cause here?

I'll see if the binding layer can do a better job of building the exception.

I think you'll find the problem comes from the namespace.

JBossXB returns null when it doesn't recognise the root element.

It is expecting a root element of:

{jboss-namespace}:jboss

but since it is using the dtd, it is actually getting

{}:jboss

i.e. no namspace.

JBossXB should be fixed generically to throw a message like
:jboss is not a root element {jboss-namespace}:jboss
but equally, JBossXB should be able to "fixup" the namespace
for the case when one isn't provided if you know upfront what the namespace should be.