Invalid get_string() identifier: 'sectionname' or component 'format_tiles'. Perhaps you are missing $string['sectionname'] = ''; in /lang/en/format_tiles.php?

• line 356 of /lib/classes/string_manager_standard.php: call to debugging()
• line 7024 of /lib/moodlelib.php: call to core_string_manager_standard->get_string()
• line 352 of /mod/forum/index.php: call to get_string()

The 'tiles' course format does not define the format_tiles\output\renderer renderer class. This is required since Moodle 4.0.

• line 1540 of /course/format/classes/base.php: call to debugging()
• line 3573 of /course/lib.php: call to core_courseformat\base->get_renderer()
• line 101 of /theme/catawesome/layout/drawers.php: call to core_course_drawer()
• line 1485 of /lib/outputrenderers.php: call to include()
• line 1410 of /lib/outputrenderers.php: call to core_renderer->render_page_layout()
• line 458 of /mod/forum/index.php: call to core_renderer->header()