SQL-DATABASE ERROR

Database error in WoltLab Burning Board (2.3.6): Invalid SQL: SELECT b.*, t.topic, t.prefix AS threadprefix, i.* FROM bb1_boards b LEFT JOIN bb1_threads t ON (t.threadid=b.lastthreadid) LEFT JOIN bb1_icons i USING (iconid) ORDER by b.parentid ASC, b.boardorder ASC
mysql error: Out of resources when opening file './usr_web1_2/bb1_boards.MYD' (Errcode: 24)
mysql error number: 23
mysql version: 5.5.47-0+deb6u1-log
php version: 5.3.3-7+squeeze29
Date: 05.07.2020 @ 21:33
Script: /board.php?boardid=71&page=1&daysprune=1000&sortfield=replycount&sortorder=ASC
Referer: