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 172 of /mod/url/locallib.php: call to core_renderer->header()
• line 259 of /mod/url/locallib.php: call to url_print_header()
• line 104 of /mod/url/view.php: call to url_print_workaround()