Plugin is not activated

Hi, i got this error in version 2.0.0. Thanks.

Fatal error: Uncaught Error: Class 'FROU\Plugin_Core' not found in /var/www/vhosts/ccc.com/httpdocs/wp-content/plugins/file-renaming-on-upload/file-renaming-on-upload.php:29 Stack trace: #0 /var/www/vhosts/ccc.com/httpdocs/wp-admin/includes/plugin.php(1882): include() #1 /var/www/vhosts/ccc.com/httpdocs/wp-admin/plugins.php(164): plugin_sandbox_scrape('file-renaming-o...') #2 {main} thrown in /var/www/vhosts/ccc.com/httpdocs/wp-content/plugins/file-renaming-on-upload/file-renaming-on-upload.php on line 29