Edit PDF assignment thing defines a bad foreign key

ERROR:  relation "q_assign_grade" does not exist

LINE 1: ...) FROM q_assignfeedback_editpdf_cmnt t1 LEFT JOIN q_assign_g...

                                                             ^

SELECT  count(1) FROM q_assignfeedback_editpdf_cmnt t1 LEFT JOIN q_assign_grade  t2 ON t1.gradeid = t2.id WHERE t1.gradeid <> $1 AND t2.id IS NULL

[array (

  0 => '0',

)]

Error code: dmlreadexceptionStack trace: line 441 of /lib/dml/moodle_database.php: dml_read_exception thrownline 239 of /lib/dml/pgsql_native_moodle_database.php: call to moodle_database->query_end()line 744 of /lib/dml/pgsql_native_moodle_database.php: call to pgsql_native_moodle_database->query_end()line 1415 of /lib/dml/moodle_database.php: call to pgsql_native_moodle_database->get_records_sql()line 1488 of /lib/dml/moodle_database.php: call to moodle_database->get_record_sql()line 1659 of /lib/dml/moodle_database.php: call to moodle_database->get_field_sql()line  105 of  /admin/tool/xmldb/actions/check_foreign_keys/check_foreign_keys.class.php:  call to moodle_database->count_records_sql()line 159 of /admin/tool/xmldb/actions/XMLDBCheckAction.class.php: call to check_foreign_keys->check_table()line 69 of /admin/tool/xmldb/index.php: call to XMLDBCheckAction->invoke()