Fatal error: Link-ID == false, Verbindung fehlgeschlagen

Error Message: Link-ID == false, Verbindung fehlgeschlagen
Error Code: 2054
SQL Type: Database
SQL Error: The server requested authentication method unknown to the client
SQL Error Number: 2054
SQL Version:
File: /var/www/web621/html/v2/lib/database/Database.class.php (76)
PHP Version: 5.6.30
GUI Version: 2.6.5
DB Build: 1063
Date: Mon, 24 Jul 2017 04:46:57 +0000
Request: /
Referer:

Stacktrace:

#0 /var/www/web621/html/v2/lib/database/Database.class.php(60): Database->connect()
#1 /var/www/web621/html/v2/lib/database/Database.class.php(517): Database->__construct(...)
#2 /var/www/web621/html/v2/acp/inc/init.php(107): require_once('/var/www/web621...')
#3 /var/www/web621/html/v2/global.php(35): require_once('/var/www/web621...')
#4 /var/www/web621/html/v2/index.php(10): require_once('/var/www/web621...')
#5 {main}