Warning: Invalid argument supplied for foreach() in zen_preprocess_menu_link() (line 642 of /var/www//sites/all/themes/zen/template.php).
Warning: array_unshift() expects parameter 1 to be array, string given in zen_preprocess_menu_link() (line 651 of /var/www//sites/all/themes/zen/template.php).
I thought it was my module or subtheme, but after disabling both on my site it is still throwing warnings. It appears there is a link somewhere in Zen (or in Drupal core or a contrib module?) that is passing a class to localized options as a string instead of an array.