Need Help New Site Creation Error

When I create a new site I get the following error msg.
If I go back the new site is created, but the error message is a fail.

Warning: array_diff(): Argument #1 is not an array in /home/******/public_html/wp-content/plugins/pro-sites/pro-sites-files/modules/premium-plugins-manager.php on line 322

Warning: Cannot modify header information - headers already sent by (output started at /home/********/public_html/wp-content/plugins/pro-sites/pro-sites-files/modules/premium-plugins-manager.php:322) in /home/*******/public_html/wp-includes/pluggable.php on line 1228