Your MySQL server does not allow incoming connections from your gameserver. To fix this, you can do either of the following:

* Go into your webserver's control panel and check if there's a section called MySQL Access Hosts or something named similar. There you can add the IP address mentioned in the error. This is usually the IP of your gameserver, but it can also be slightly different, so make sure you copy and paste it exactly from the error.

* The other option is to run the following query on your SourceBans database (for example using phpMyAdmin):
GRANT ALL ON database.* TO 'username'@'ip';

You will have to replace "database" with your SourceBans database name, and "username" and "ip" with those mentioned in the error.