Cache limiter not working

Hi,

I got the following errors for Friends and Pro Sites:

Notice: The called constructor method for WP_Widget in WPMUDev_Friends_Widget is deprecated since version 4.3.0! Use

__construct()

instead. in /home/triplegr/public_html/wp-includes/functions.php on line 3892

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/triplegr/public_html/wp-includes/functions.php:3892) in /home/triplegr/public_html/wp-content/plugins/pro-sites/pro-sites-files/lib/ProSites/Helper/Session.php on line 29

Notice: get_currentuserinfo is deprecated since version 4.5.0! Use wp_get_current_user() instead. in /home/triplegr/public_html/wp-includes/functions.php on line 3829

My Memory resources get maxed out and I need help to repair this problem.

Michael