_Mooc_RC: How to do an audience analysis

Format plugin format_onetopic is not found. Using default format_topics

line 140 of /course/format/classes/base.php: call to debugging()
line 201 of /course/format/classes/base.php: call to core_courseformat\base::get_format_or_default()
line 38 of /course/format/lib.php: call to core_courseformat\base::instance()
line 3317 of /lib/modinfolib.php: call to course_get_format()
line 648 of /lib/modinfolib.php: call to section_info->__construct()
line 518 of /lib/modinfolib.php: call to course_modinfo->__construct()
line 2752 of /lib/modinfolib.php: call to course_modinfo::instance()
line 2253 of /lib/moodlelib.php: call to get_fast_modinfo()
line 2783 of /lib/moodlelib.php: call to require_login()
line 47 of /mod/url/view.php: call to require_course_login()