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 @ 02:30
Script: /wbb/usercp.php?action=addsubscription&boardid=112&sid=4785bc9f509ed2c6c2c995fc23f8286b
Referer: http://delftseschaaksite.nl/wbb/usercp.php?action=addsubscription&boardid=112&sid=4785bc9f509ed2c6c2c995fc23f8286b