This system will not add the database user to the database because this user does not have a password: MariaDB 10.4

Symptoms

When trying to assign a user to a database:

 Cpanel::Exception/(XID 68gz6x) This system will not add the database user “cptest_user” to the database “cptest_db” because this user does not have a password.

 There is no such grant defined for user 'username' on host 'localhost' 

When trying to set a new password for a user:

The system received an error from the “MySQL” database “mysql”: 1356
(View 'mysql.user' references invalid table(s) or column(s) or function(s)
or definer/invoker of view lack rights to use them)

Or:

 The system received an error from the “MySQL” database “mysql”: ER_PARSE_ERROR
 (You have an error in your SQL syntax; check the manual that corresponds to your 
MariaDB server version for the right syntax to use near '; /* passwduser */' at line 1)

Description 

These errors can occur if your server has been upgraded to the unsupported MariaDB version 10.4.

Workaround

Install a currently supported MariaDB version.

Please note there is no downgrade path. Neither cPanel, CloudLinux, nor even the MariaDB developers support a downgrade. You will need to make backups of all databases, completely remove MariaDB 10.4, install MariaDB 10.3 and then restore your databases. You may even need to rely on previous backups that you took before the upgrade to 10.4.

See Also

Does cPanel support MariaDB 10.4?