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 @ 08:14
Script: /wbb/usercp.php?action=addsubscription&threadid=6755&sid=f27e2a02d80df8f7c0dd8a5d06c2f308
Referer: http://www.delftseschaaksite.nl/wbb/usercp.php?action=addsubscription&threadid=6755&sid=f27e2a02d80df8f7c0dd8a5d06c2f308