I haven't seen that error before, but here's a possible solution; let me know if it works and I'll update the download:
open {theme-folder}\s5_admin\vertex\functions.php
change line 15 from
$new[$config_key] = '';
to
$new["$config_key"] = '';
As for the formatting problem, that may be solved by fixing the admin error, so let's see what happens with the error first.