1. Create a course, set it as Separate Groups. 2. Add Recent Activity block. 3. Enrol users, add them to groups. 4. Log in as a user, enter the course, click on "Full report of recent activity..." 5. repeat the tests for all combinations of group modes+accessallgroups+groupings Example of output: Error reading from database More information about this error Debug info: ERROR: invalid input syntax for integer: "Array" SELECT u.id,u.picture,u.firstname,u.lastname,u.imagealt,u.email FROM mdl_user u JOIN (SELECT DISTINCT eu1_u.id FROM mdl_user eu1_u JOIN mdl_groups_members eu1_gm ON (eu1_gm.userid = eu1_u.id AND eu1_gm.groupid = $1) JOIN mdl_user_enrolments eu1_ue ON eu1_ue.userid = eu1_u.id JOIN mdl_enrol eu1_e ON (eu1_e.id = eu1_ue.enrolid AND eu1_e.courseid = $2) WHERE eu1_u.deleted = 0 AND eu1_u.id <> $3) je ON je.id = u.id WHERE u.deleted = 0 ORDER BY u.lastname ASC, u.firstname ASC [array ( 0 => array ( 0 => 178, ), 1 => '378', 2 => '1', )] Stack trace: line 391 of /lib/dml/moodle_database.php: dml_read_exception thrown line 232 of /lib/dml/pgsql_native_moodle_database.php: call to moodle_database->query_end() line 678 of /lib/dml/pgsql_native_moodle_database.php: call to pgsql_native_moodle_database->query_end() line 3259 of /lib/accesslib.php: call to pgsql_native_moodle_database->get_records_sql() line 63 of /course/recent_form.php: call to get_enrolled_users() line 152 of /lib/formslib.php: call to recent_form->definition() line 59 of /course/recent.php: call to moodleform->moodleform()