We have 5 servers in a cluster (1-ISP Host, 2-DNS Severs, 1-Web Server, 1-DB Server - all running Jessie 8.6), that have stopped synchronizing. All servers were fully synchronizing as of 4 hours ago. I started adding and editing zone files earlier today with no problems. Later on, I started adding and editing more zones (we are migrating from older servers) and the synchronization never completed. I ran across https://www.howtoforge.com/community/threads/move-primary-dns-and-sql.74202/ and ran the server.sh script on all servers. All servers are throwing errors similar to: PHP Warning: mysqli_connect(): (28000/1045): Access denied for user 'ispcsrv5'@'FQDN'(using password: YES) in /usr/local/ispconfig/server/lib/classes/db_mysql.inc.php on line 85 Zugriff auf Datenbankserver fehlgeschlagen! / Database server not accessible!24.01.2017-20:14 - WARNING - Unable to connect to local server. PHP Warning: mysqli_ping() expects parameter 1 to be mysqli, null given in /usr/local/ispconfig/server/lib/classes/db_mysql.inc.php on line 198 PHP Warning: mysqli_connect(): (28000/1045): Access denied for user 'ispcsrv5'@'FQDN'(using password: YES) in /usr/local/ispconfig/server/lib/classes/db_mysql.inc.php on line 200 I've checked the MySQL DBs on all servers and none have a MySQL user of [email protected] How can I get past this issue? Why are the ispcsrvx users missing? As mentioned, this has been working flawlessly but changed in a matter of a couple of hours with no modifications other than the DNS edits. These servers are serving the DNS zones that are configured but we cannot add new zones or modify the existing zones. Your help is realty appreciated.