During an upgrade, Parallels Plesk Panel needs to connect to the local MySQL server. If it's not possible, the upgrade fails:
WARNING: [MYSQL ERROR] Unable to connect to database. the reason of problem:
ERROR: The system was not able to find the specified registry key or value.
WARNING: Default MySQL server is not registered in Parallels Plesk Panel. If you use custom MySQL instances you should register one at least according to article /en/111983
Plesk Panel is not able to connect to database.
Make sure that it is possible to connect to the local MySQL server with this command:
"%plesk_dir%\\MySQL\\bin\\mysql.exe" -uadmin -p<password> -hlocalhost -P3306
A password can be obtained by this command:
"%plesk_bin%\\dbclient.exe" --direct-sql --sql="select * from databaseservers where type='mysql' and host='localhost'"
id host port type server_version admin_login admin_password parameters_id last_error
1 localhost 3306 mysql 5.5.15 admin e*********e no_error
If you can't login to MySQL server with your credentials, you have to change your credentials in
databaseservers to validate your MySQL server. You can do so with this command:
"%plesk_bin%\\dbclient.exe" --direct-sql --sql="Update databaseservers set admin_login='<MySQL user name>', admin_password='<type password here>' where host='localhost' and type='mysql'"
<MySQL user name> - it is the name of the user with all privileges.