SQL-DATABASE ERROR

Database error in WoltLab Burning Board: Link-ID == false, connect failed
mysql error: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
mysql error number: 2002
Date: 21.05.2024 @ 00:28
Script: /wbb/usercp.php?action=addsubscription&boardid=111&sid=818a41fa6ec467f3b8627850e00b1741
Referer: http://delftseschaaksite.nl/wbb/usercp.php?action=addsubscription&boardid=111&sid=818a41fa6ec467f3b8627850e00b1741