This means that your bank uses Apache Cocoon to develop their website, and they have a problem with it. We at Apache cannot really help you with a problem on your bank's site - you'll have to find a way to contact them directly.
Do we still have that copy in the error pages? If so I think it should be removed. Its audience is developers, who already know that information. But when the developers don't provide custom error pages for applications that face out into the wilderness... ;-/
OK I just checked, it's still in error2html.xsl. In exception2html.xsl, it's commented out, with a comment that says the same as what I said above... :-)
—ml—
