I am getting the same error. I have tried all that you have but no luck.

Error while executing: SET NAMES 'utf-8';
Unknown system variable 'NAMES'Error while executing: ALTER DATABASE DEFAULT CHARACTER SET 'utf8' COLLATE 'utf8_unicode_ci';
You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near 'DATABASE DEFAULT CHARACTER SET 'utf8' COLLATE 'utf8_unicode_ci'