Call to undefined method ProSites on line 3146

Hi,

I got these errors from old time onwards with Pro Sites plugin:

[Tue Jan 10 14:54:24.174537 2017] [:error] [pid 9105] [client 104.236.209.45:56080] FastCGI: server "/var/www/cgi-bin/php5-fcgi" stderr: PHP message: PHP Fatal error: Call to undefined method ProSites::get_profile_id() in /var/www/web/wp-content/plugins/pro-sites/pro-sites-files/gateways/gateway-paypal-express-pro.php on line 3146, referer: http://dedaconstruction.com/wp-cron.php?doing_wp_cron=1484078063.9794800281524658203125

[Tue Jan 10 14:54:24.210661 2017] [:error] [pid 6891] [client 66.249.69.6:59715] FastCGI: server "/var/www/clients/client0/web1/cgi-bin/php5-fcgi" stderr: PHP message: PHP Fatal error: Call to undefined method ProSites::get_profile_id() in /var/www/web/wp-content/plugins/pro-sites/pro-sites-files/gateways/gateway-paypal-express-pro.php on line 3146

They expired and should now be running on the free level.
I'm using the newest version of this plugin ( v3.5.4 ).

Please fix it as soon as possible.

Thanks,
Adam