Fatal error: Connecting to MySQL server 'mis52.de' failed.

You get more information about the problem in our knowledge base: http://www.woltlab.com/help/?code=2005

Information:

error message: Connecting to MySQL server 'mis52.de' failed.
error code: 2005
sql type: MySQLDatabase
sql error: Unknown MySQL server host 'mis52.de' (110)
sql error number: 2005
sql version:
file: /var/www/web1/html/boards/support/wcf/lib/system/database/MySQLDatabase.class.php (29)
php version: 5.3.29
wcf version: 1.0.11 pl 4 (Horizon)
date: Wed, 12 May 2021 23:56:57 +0000
request: /index.php?page=Help&item=register.register&s=4f75a20253dbf6642f1f5ce5df4720cf1e37ad5d
referer:

Stacktrace:

#0 /var/www/web1/html/boards/support/wcf/lib/system/database/Database.class.php(76): MySQLDatabase->connect()
#1 /var/www/web1/html/boards/support/wcf/lib/system/WCF.class.php(270): Database->__construct(...)
#2 /var/www/web1/html/boards/support/wcf/lib/system/WCF.class.php(88): WCF->initDB()
#3 /var/www/web1/html/boards/support/global.php(20): WCF->__construct()
#4 /var/www/web1/html/boards/support/index.php(7): require_once('/var/www/web1/h...')
#5 {main}