Hi! When I tried to render an org-mode document containing a ditaa block, an error: "Could not find ditaa.jar at /Users/username/.emacs.d/elpa/contrib/scripts/ditaa.jar". In fact the whole contrib folder was missing, and ditaa.jar wasn't anywhere on my disk.
After a long search for problems with my configuration, I solved the problem by downloading the sources and copying the contrib folder manually, but shouldn't it be included in the org-plus-contrib package or at least be available as a separate one? Best regards, Pascal Lorenz