Fatal error

Hi there!
My website was not loading (only the header and footer). My hosting provider’s supports has checked and told me that the Download Manager is one of the plugins giving me trouble.
After restoring the site, if I try to activate WPDM I get this message:
Plugin could not be activated because it triggered a fatal error.

Registration is disabled!

Fatal error: Uncaught Error: Class 'WPDM\Email' not found in /home2/thecorv5/public_html/wp-content/plugins/download-manager/admin/class.WordPressDownloadManagerAdmin.php:25 Stack trace: #0 /home2/thecorv5/public_html/wp-content/plugins/download-manager/admin/class.WordPressDownloadManagerAdmin.php(17): WPDM\admin\WordPressDownloadManagerAdmin->Actions() #1 /home2/thecorv5/public_html/wp-content/plugins/download-manager/download-manager.php(135): WPDM\admin\WordPressDownloadManagerAdmin->__construct() #2 /home2/thecorv5/public_html/wp-content/plugins/download-manager/download-manager.php(104): WPDM\WordPressDownloadManager->__construct() #3 /home2/thecorv5/public_html/wp-content/plugins/download-manager/download-manager.php(475): WPDM\WordPressDownloadManager::instance() #4 /home2/thecorv5/public_html/wp-admin/includes/plugin.php(2300): include('/home2/thecorv5...') #5 /home2/thecorv5/public_html/wp-admin/plugins.php(191): plugin_sandbox_scrape('download-manage...') #6 {main} thrown in /home2/thecorv5/public_html/wp-content/plugins/download-manager/admin/class.WordPressDownloadManagerAdmin.php on line 25

The page I need help with: [log in to see the link]