when trying to activate plugin

when i try to enable the plugin for supporter advertising i get the error:

Fatal error: Cannot redeclare supporter_advertising_localization() (previously declared in /home/username/public_html/wp-content/plugins/pro-sites/pro-sites-files/modules/supporter-advertising.php:71) in /home/username/public_html/wp-content/plugins/supporter-advertising/supporter-advertising.php on line 72