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 '/tmp/mysql5.sock' (2)
mysql error number: 2002
mysql version: unknown
php version: 5.3.10-1ubuntu3.26
Date: 26.09.2022 @ 12:05
Script: /forum/wbb2/thread.php?threadid=1309
Referer: