Today I get this error message. Installed the last versione of xampp for linux (php 7). The permissions of the mysql data are user: nobody, group: nogroup, with pemissions rw for all.
This is a problem of all the tables of all databases. I access as root with password and I see granted all privileges...
Here: "Grants for root@localhost
GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED BY PASSWORD '*3DDB6F1DCB51287BC6DFA27177DDD805ACAE1224' WITH GRANT OPTION
GRANT PROXY ON ''@'%' TO 'root'@'localhost' WITH GRANT OPTION"