Plesk login shows ERROR PleskMainDBException Access denied for user 'admin'@'localhost' (using password: YES)

Updated October 05, 2021 09:08

Plesk for Windows kb: technical ABT: Group B

Applicable to:

After upgrading Plesk on Windows or after changing the admin password, the following error is shown instead of the Plesk login page:

CONFIG_TEXT: Access denied for user 'admin'@'localhost' (using password: YES)

An incorrect password is set for the user admin in the MySQL database.

Connect to the server via RDP.
Open cmd.exe as Administrator and create the password registry entry, specifying a new password:

C:\> plesk sbin psadb -u --password="new_password"
Add the skip-grant-tables option in [PleskSQLServer] section of the file %plesk_dir%MySQL\my.ini:

CONFIG_TEXT: [PleskSQLServer]
skip-grant-tables
Restart the Plesk SQL Server service:

C:\> net stop PleskSQLServer && net start PleskSQLServer
Check database server version and proceed accordingly:

# mysql --version

Change the admin password in the database:

For MySQL 5.7.5 and earlier or MariaDB 10.1.20 and earlier

C:\> plesk db "update mysql.user set authentication_string=password('new_password') where user='admin'"

For MySQL 5.7.6 and newer or MariaDB 10.1.21 and newer

C:\> plesk db

MYSQL_WIN: use mysql;

MYSQL_WIN: FLUSH PRIVILEGES;

MYSQL_WIN: DROP USER 'admin'@'localhost';

MYSQL_WIN: CREATE USER 'admin'@'localhost' IDENTIFIED VIA mysql_native_password USING PASSWORD('new_password');

MYSQL_WIN: GRANT ALL ON . TO 'admin'@'localhost' WITH GRANT OPTION;

MYSQL_WIN: exit

Remove the skip-grant-tables from %plesk_dir%MySQL\my.ini and restart the service again (repeat step #3).
Run the following commands in Command Prompt to update the password in Windows registry:

C:\> plesk sbin psadb -u --password="new_password"
plesk sbin psadb -s --password="new_password"