Fatal error: Connecting to MySQL server 'mysql7.1blu.de' failed.

You get more information about the problem in our knowledge base: http://www.woltlab.com/help/?code=2054

Information:

error message: Connecting to MySQL server 'mysql7.1blu.de' failed.
error code: 2054
sql type: MySQLDatabase
sql error: The server requested authentication method unknown to the client
sql error number: 2054
sql version:
file: /hp/bl/ab/oh/www/enigma/forum/wcf/lib/system/database/MySQLDatabase.class.php (29)
php version: 5.6.11-1+deb.sury.org~precise+1
wcf version: 1.0.11 pl 4 (Horizon)
date: Wed, 02 Sep 2015 00:15:43 +0000
request: /enigma/forum/index.php/index.php/index.php?page=User&userID=413
referer:

Stacktrace:

#0 /hp/bl/ab/oh/www/enigma/forum/wcf/lib/system/database/Database.class.php(76): MySQLDatabase->connect()
#1 /hp/bl/ab/oh/www/enigma/forum/wcf/lib/system/WCF.class.php(270): Database->__construct(...)
#2 /hp/bl/ab/oh/www/enigma/forum/wcf/lib/system/WCF.class.php(88): WCF->initDB()
#3 /hp/bl/ab/oh/www/enigma/forum/global.php(18): WCF->__construct()
#4 /hp/bl/ab/oh/www/enigma/forum/index.php(7): require_once('/hp/bl/ab/oh/ww...')
#5 {main}