Default exception handler: Coding error detected, it must be fixed by a programmer: PHP catchable fatal error Debug: Argument 1 passed to global_navigation::add_course_essentials() must be an instance of navigation_node, boolean given, called in /lib/navigationlib.php on line 1173 and defined

* line 359 of /lib/setuplib.php: coding_exception thrown

* line 2171 of /lib/navigationlib.php: call to default_error_handler()

* line 1173 of /lib/navigationlib.php: call to global_navigation->add_course_essentials()

* line 2571 of /lib/navigationlib.php: call to global_navigation->initialise()

* line 659 of /lib/pagelib.php: call to navbar->has_items()

* line 4 of /theme/moodleofficial/layout/general.php: call to moodle_page->has_navbar()

* line 654 of /lib/outputrenderers.php: call to include()

* line 612 of /lib/outputrenderers.php: call to core_renderer->render_page_layout()

* line ? of unknownfile: call to core_renderer->header()

* line 1279 of /lib/setuplib.php: call to call_user_func_array()

* line 2354 of /lib/weblib.php: call to bootstrap_renderer->__call()

* line 2354 of /lib/weblib.php: call to bootstrap_renderer->header()

* line 2495 of /lib/moodlelib.php: call to notice()

* line 2741 of /lib/moodlelib.php: call to require_login()

* line 47 of /mod/forum/discuss.php: call to require_course_login()