The most common reason for this is that there is either a password assigned to the MySQL root user that is stored in the Qube configuration file in an encrypted format, or (Windows only) that the MySQL server has been modified to not use the skip-grant-options variable in the MySQL server's my.cnf.

Working around the MySQL root user password 

If possible, set the root user to have no password for the duration of your install, and then re-set the password once finished.

There is also an alternate method if you cannot reset the password. Define the MySQL root user password in the Qube configuration file, qb.conf, by adding these lines:

database_user = root
database_password = "yourpassword"

The database_password must be stored in cleartext for the installer to be able to use it, the installer is not capable of decrypting an encrypted password.

You can use any account you wish. However the user account you choose must be capable of creating and deleting databases.

Working around a Windows MySQL server running with skip-grant-grant-options disabled:

You will need to edit the MySQL configuration file my.cnf, adding or uncommenting the following line to the [mysqld] section:

skip-grant-options

Then stop the Qube supervisor service, restart the MySQL service, and perform the upgrade.  Once the upgrade has completed, you may again disable the skip-grant-options variable by removing or commenting-out the relevant line in the my.cnf, and restarting the MySQL service

See Also:

Where is the qb.conf file?

Where is the MySQL configuration file?