After deleting a course, http://hub.moodle.org/local/hub/admin/managecourses.php gives the error

Error reading from database

More information about this error

Debug info: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') AND site.id = course.siteid GROUP BY siteid' at line 1
SELECT site.* FROM mdl_hub_course_directory course, mdl_hub_site_directory site WHERE course.id IN () AND site.id = course.siteid GROUP BY siteid
[array (
)]
Stack trace:
line 394 of /lib/dml/moodle_database.php: dml_read_exception thrown
line 889 of /lib/dml/mysqli_native_moodle_database.php: call to moodle_database->query_end()
line 225 of /local/hub/admin/managecourses.php: call to mysqli_native_moodle_database->get_records_sql()