The database server could be connected to (which means your username and password is okay) but the 9hieucom_NDgwZjI4MjVmYWZlZG_dbname
database could not be selected.
9hieucom_NDgwZjI4MjVmYWZlZG_username
have permission to use the 9hieucom_NDgwZjI4MjVmYWZlZG_dbname
database?username_9hieucom_NDgwZjI4MjVmYWZlZG_dbname
. Could that be the problem?If you do not know how to set up a database you should contact your host. If all else fails you may find help at the WordPress support forums.