Unable to start MySQL in Plesk: Missing system table mysql.roles_mapping; please run mysql_upgrade to create it

Symptoms

• Unable to start MySQL service. The following error is present in system log (/var/log/messages, /var/log/syslog, /var/log/mariadb/mariadb.log, /var/log/mysql/mysql.log,
  %plesk_dir%MySQLData<SERVER_NAME>.err):

  [ERROR] Missing system table mysql.roles_mapping; please run mysql_upgrade to create it

  ---

  InnoDB: Error: Fetch of persistent statistics requested for table "table_name"."database_name" but the required system tables mysql.innodb_table_stats and mysql.innodb_index_stats are not present or have unexpected structure. Using transient stats instead.

• Plesk interface might be inaccessible with the following error:

  ERROR: Zend_Db_Adapter_Exception: SQLSTATE[HY000] [2002] No such file or directory

• Clicking at Plesk > Domains > example.com > Databases results in the error:

  PLESK_ERROR: Unknown column ‘Event_priv’ in ‘field list

Cause

Failed MySQL upgrade or corrupted installation.

Resolution

1. Connect to the server using SSH/RDP;

2. Complete the MySQL upgrade or re-create missing system tables using the following command:

   On Linux:

   # mysql_upgrade -u admin -p`cat /etc/psa/.psa.shadow` –force

   On Windows

   C:> “C:Program FilesMySQLMySQL Server 5.7binmysql_upgrade.exe” -uadmin -P3306 -p mysql_admin_password