SQL-DATABASE ERROR

Database error in WoltLab Burning Board (): Link-ID == false, connect failed
mysql error: Too many connections
mysql error number: 1040
mysql version: unknown
php version: 5.3.10-1ubuntu3.10
Date: 22.10.2018 @ 09:02
Script: /bb/board.php?boardid=100&sid=07e527819af81e8bc14820c7c5213fd7
Referer: