PHP error on admin/structure/semantic_fields/list/ordered_list/edit

Can't add or edit any preset. Here is my PHP log:

[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP Fatal error:  Unsupported operand types in /includes/form.inc on line 1759, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP Stack trace:, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP   1. {main}() /index.php:0, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP   2. menu_execute_active_handler() /index.php:21, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP   3. call_user_func_array() /includes/menu.inc:517, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP   4. ctools_export_ui_switcher_page() /includes/menu.inc:0, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP   5. call_user_func_array() /modules/ctools/includes/export-ui.inc:469, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP   6. ctools_export_ui->edit_page() /modules/ctools/includes/export-ui.inc:0, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP   7. ctools_export_ui->edit_execute_form() /modules/ctools/plugins/export_ui/ctools_export_ui.class.php:703, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP   8. ctools_export_ui->edit_execute_form_standard() /modules/ctools/plugins/export_ui/ctools_export_ui.class.php:770, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP   9. drupal_build_form() /modules/ctools/plugins/export_ui/ctools_export_ui.class.php:780, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP  10. drupal_process_form() /includes/form.inc:374, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP  11. form_builder() /includes/form.inc:842, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP  12. form_builder() /includes/form.inc:1857, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP  13. form_builder() /includes/form.inc:1857, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP  14. form_builder() /includes/form.inc:1857, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP  15. form_builder() /includes/form.inc:1857, referer: http://example.com/admin/structure/semantic_fields
[Fri Apr 26 14:27:01 2013] [error] [client 127.0.0.1] PHP  16. form_builder() /includes/form.inc:1857, referer: http://example.com/admin/structure/semantic_fields