[O] Further problems with export

[Neuwirth Erich]

After being able to build again,
I cannot export now.

In my .emacs I have


;; using the new exporter
(define-key org-mode-map (kbd "C-c C-e") 'org-export-dispatch)


When I try to export with
C-c C-e 
I get a window with the menu for the export commands,
and a prompt
Export command:
in the bottom line (minibuffer window)
When I then press 
h (one of the highlighted keys)
the shortcut keys listed under the 
Export to HTML item become highlighted (red)
and when I then press
o
which should export to html and open the file
the minibuffer displays
Symbol's function definition is void: org-export-blocks-preprocess

The same problem occurs for any other export option I tried.


How can I make things work again?