#+OPTIONS: html-preamble:"<p class='author'>Author: %a<br/>(%e)</p><p class='date'>Date: %d</p><p><img src='./img/SemBSDD-Logo-400px.png'/></p>"
C-c happily says "Local setup has been refreshed" But then C-c C-e h h complains: "org-export--parse-option-keyword: End of file during parsing". I don't see any problem in the string; evaluating it in *scratch* returns it just fine. But I think org-export--parse-option-keyword uses some limited reader...