WordPress Errors when activating Multi-DB

Installed Multi-DB on a the latest WP-MU I believe I did everything correct also got all greens on step 5 but when activating the plugin I get these errors:

Warning: mysql_set_charset() expects parameter 2 to be resource, boolean given in /home/domain/public_html/wp-includes/wp-db.php on line 641

Warning: Cannot modify header information - headers already sent by (output started at /home/domain/public_html/wp-includes/wp-db.php:641) in /home/domain/public_html/wp-includes/pluggable.php on line 695