Hook callback definition contains invalid 'callback' class name in 'mod_subsection'. Callback class 'mod_subsection\local\callbacks\before_activitychooserbutton_exported_handler' not found.
line 230 of /lib/classes/hook/manager.php: call to debugging()
line 190 of /lib/classes/hook/manager.php: call to core\hook\manager->is_callback_valid()
line 309 of /lib/classes/hook/manager.php: call to core\hook\manager->getListenersForEvent()
line 70 of /course/classes/output/activitychooserbutton.php: call to core\hook\manager->dispatch()
line 371 of /course/format/classes/output/local/content/cm.php: call to core_course\output\activitychooserbutton->export_for_template()
line 139 of /course/format/classes/output/local/content/cm.php: call to core_courseformat\output\local\content\cm->add_actvitychooserbutton_data()
line 107 of /course/format/classes/output/local/content/section/cmitem.php: call to core_courseformat\output\local\content\cm->export_for_template()
line 122 of /course/format/classes/output/local/content/section/cmlist.php: call to core_courseformat\output\local\content\section\cmitem->export_for_template()
line 241 of /course/format/classes/output/local/content/section.php: call to core_courseformat\output\local\content\section\cmlist->export_for_template()
line 172 of /course/format/classes/output/local/content/section.php: call to core_courseformat\output\local\content\section->add_cm_data()
line 92 of /course/format/classes/output/local/content/frontpagesection.php: call to core_courseformat\output\local\content\section->export_for_template()
line 87 of /lib/classes/output/plugin_renderer_base.php: call to core_courseformat\output\local\content\frontpagesection->export_for_template()
line 88 of /course/format/classes/output/section_renderer.php: call to core\output\plugin_renderer_base->render()
line 1608 of /course/renderer.php: call to core_courseformat\output\section_renderer->render()
line 136 of /index.php: call to core_course_renderer->frontpage_section1()