I read all the previous answers but I didn't find any solution to this error. I ended going to the MySQL Workbench and checked the list of "Users and Privileges" from the "Server" menu. There I already had the root username along with host '%' and verified all of its permissions and privileges, but even with that it was not working. I created another 'root' user with host '172.16.9.xx' (the IP address of my virtual server), assigned the corresponding roles and privileges to it, then I reset the MySQL and that was it. Problem SOLVED !!