When the mysql version on plesk server get's upgraded we get an error while adding an user to the database (please check the below given screen shot ):

To vanish the above error just follow mentioned steps:
That's it now you will not get the error again!!
Error: Connection to the database server has failed: Table 'mysql.servers' doesn't exist

To vanish the above error just follow mentioned steps:
Step 1: SSH to your server
Step 2: Open mysql by typing:
mysql -u YOURUSERNAMEHERE -p
Here YOURUSERNAMEHERE=Your actual user name which you are going to use.
Hit enter, you’ll be asked for your mysql password.
Step 3: Use the mysql database:
USE mysql;
Step 4: Place this code in to create the table:
CREATE TABLE `servers` (
`Server_name` char(64) NOT NULL,
`Host` char(64) NOT NULL,
`Db` char(64) NOT NULL,
`Username` char(64) NOT NULL,
`Password` char(64) NOT NULL,
`Port` int(4) DEFAULT NULL,
`Socket` char(64) DEFAULT NULL,
`Wrapper` char(64) NOT NULL,
`Owner` char(64) NOT NULL,
PRIMARY KEY (`Server_name`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8
COMMENT='MySQL Foreign Servers table';
Step 2: Open mysql by typing:
mysql -u YOURUSERNAMEHERE -p
Here YOURUSERNAMEHERE=Your actual user name which you are going to use.
Hit enter, you’ll be asked for your mysql password.
Step 3: Use the mysql database:
USE mysql;
Step 4: Place this code in to create the table:
CREATE TABLE `servers` (
`Server_name` char(64) NOT NULL,
`Host` char(64) NOT NULL,
`Db` char(64) NOT NULL,
`Username` char(64) NOT NULL,
`Password` char(64) NOT NULL,
`Port` int(4) DEFAULT NULL,
`Socket` char(64) DEFAULT NULL,
`Wrapper` char(64) NOT NULL,
`Owner` char(64) NOT NULL,
PRIMARY KEY (`Server_name`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8
COMMENT='MySQL Foreign Servers table';
