Go to your home directory. You can use cpanel’s File Manager. Or you can access your home directory through ftp. Find a file called my.cnf. Rename it to my.cnf.backup.

What will happen? You probably changed your cpanel password. The new password was not updated in my.cnf. By deleting this file, the next time you login to cpanel, it will have to recreate it with your new password. And that will solve your mysql backup problem.

The mysql backup process uses that file to access the mysql databases. If the password is incorrect, the cpanel process will be denied access to those databases. You will not see any error, because it’s not logged in your cpanel interface. But you will get an empty database backup instead.