Since upgrading to org-mode 9.0, I am unable to export HTML blocks. When I
export to HTML, the contents of HTML blocks export literally, rather than
as rendered HTML.

So for instance, I have an org-mode file containing this:

#+BEGIN_HTML
<A HREF="http://orgmode.org">link</a>
#+END_HTML

When I export to HTML, I get an HTML file that has the literal text "<A
HREF="http://orgmode.org">link</a>" rather than creating a hyperlink.

Is there a fix for this? Thanks!