SQL-DATABASE ERROR

Database error in WoltLab Burning Board (2.3.6): Invalid SQL: SELECT postid FROM bb1_posts WHERE threadid = '174674' AND visible = 1 ORDER BY posttime ASC LIMIT 0, 20
mysql error: Out of resources when opening file './usr_web1_2/bb1_posts.MYD' (Errcode: 24)
mysql error number: 23
mysql version: 5.5.47-0+deb6u1-log
php version: 5.3.3-7+squeeze29
Date: 07.07.2020 @ 17:28
Script: /print.php?threadid=174674&page=1
Referer: