Cannot remove MySQL database: There is no such grant defined for user on host

Symptoms

• The database "example" cannot be removed
• It is not possible to assign an existing user to it in Domains > example.com > Databases > User Management > dbuser > Database section.
• When attempting to perform such actions the following error appears:
  

  There is no such grant defined for user on host

• MySQL query shows the following grants set for 'user':
  

  # plesk db "SHOW GRANTS FOR 'user';"
  | Grants for user@%                                              |            
  | GRANT USAGE ON . TO 'user'@'%' IDENTIFIED BY PASSWORD '*****'  |            
  1 rows in set (0.00 sec)

Cause

Insufficient permissions for the database user over the database.

Resolution

1. Connect to the server via SSH
2. Log into MySQL
3. Grant all missing privileges for the user over database example:
   

   mysql> GRANT ALL ON `example`.* TO 'user'@'%';