SQL-DATABASE ERROR

Database error in WoltLab Burning Board (2.2.1): Invalid SQL: SELECT * FROM bb1_jgs_galerie_bilder WHERE kategorie='' AND gesperrt='0' ORDER BY datum DESC LIMIT -20, 20
mysql error: 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 '-20, 20' at line 1
mysql error number: 1064
mysql version: 5.5.62-0ubuntu0.14.04.1
php version: 5.5.9-1ubuntu4.29
Date: 18.08.2019 @ 14:13
Script: /jgs_galerie_kategorie.php?action=alles&aktuelleseite=1&kategorie=3&
Referer: