Quiz - Attempting Quiz throws a PHP notice

1) login as a student
2) goto Features Demo course
3) attempt quiz with a password

Notice: Undefined offset: 0 in /html/mod/quiz/lib.php on line 1576
Call Stack

1. Time Memory Function Location
   1 0.0006 753112 {main}

   ( ) ../view.php:0
   2 0.2808 61710896 core_renderer->header( ) ../view.php:214
   3 0.2867 62348640 core_renderer->render_page_layout( ) ../outputrenderers.php:612
   4 0.2869 62438256 include( '/html/theme/binarius/layout/general.php' ) ../outputrenderers.php:654
   5 0.3391 69826000 block_manager->region_has_content( ) ../general.php:6
   6 0.3391 69826000 block_manager->ensure_content_created( ) ../blocklib.php:349
   7 0.3392 69826312 block_manager->create_block_contents( ) ../blocklib.php:954
   8 0.4045 73497664 block_base->get_content_for_output( ) ../blocklib.php:902
   9 0.4045 73500512 block_base->formatted_contents( ) ../moodleblock.class.php:232
   10 0.4045 73500512 block_settings->get_content( ) ../moodleblock.class.php:280
   11 0.4050 73571328 moodle_page->__get( ) ../pagelib.php:0
   12 0.4050 73571480 moodle_page->magic_get_settingsnav( ) ../pagelib.php:615
   13 0.4051 73580632 settings_navigation->initialise( ) ../pagelib.php:599
   14 0.4051 73580776 settings_navigation->load_module_settings( ) ../navigationlib.php:2718
   15 0.4067 73590408 quiz_extend_settings_navigation( ) ../navigationlib.php:3310