Hi,
After upgrading to org-mode 9.0, I'm getting the same error described here: https://lists.gnu.org/archive/html/emacs-orgmode/2013-05/msg01312.html. Basically LaTeX export stops with an error - pdflatex complains that it cannot write .log file, when I export a subtree with EXPORT_FILE_NAME containing a subdirectory. Best, Joon
