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' (111)
mysql error number: 2002
mysql version: unknown
php version: 5.3.3-7+squeeze29
Date: 06.07.2020 @ 13:54
Script: /usercp.php?action=buddy&add=2419
Referer: