Just remembered:
A few days ago I googled the error, and I got a few hits re Zimbra
administration that didn't relate directly to this problem. Though I
know little about Java & Javascript, it appears the system requests the
list of features, but either no (or an unexpected) response is returned.
I have Javascript enabled (and have disabled all extensions in
Firefox), yet using your (very similar) browser, the system functions
correctly.
Now I had previously used the system to configure notifications and call
screening, whereas it seems your first time using the system was *after*
the new feature was implemented. Our browsers are close enough that we
can almost rule out the browser as the culprit. As I'm in Michigan and
you're in Massachusetts, i.e., different markets, it's unlikely that
we're accessing the exact same system. So it seems the system works
under some conditions and not others, making the cause of this error
more difficult to troubleshoot.
I still have the error, but at least now I have a much better
understanding of the issues at hand, which is what I was after.
Thanks for your response,
Margaret