Fatal error on plugin activation

Fatal error: Uncaught TypeError: Return value of VirgilSecurityPure\Core\CoreProtocol::init() must be an instance of Virgil\PureKit\Protocol\Protocol, null returned in /home/s762/html/wp-content/plugins/virgil-pure/admin/core/Core/CoreProtocol.php:76 Stack trace: #0 /home/s762/html/wp-content/plugins/virgil-pure/admin/core/Background/MigrateBackgroundProcess.php(75): VirgilSecurityPure\Core\CoreProtocol->init() #1 /home/s762/html/wp-content/plugins/virgil-pure/admin/class-virgil-pure-admin.php(221): VirgilSecurityPure\Background\MigrateBackgroundProcess->__construct(Object(VirgilSecurityPure\Core\CoreProtocol)) #2 /home/s762/html/wp-includes/class-wp-hook.php(286): Virgil_Pure_Admin->virgil_pure_init_background_processes(”) #3 /home/s762/html/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array) #4 /home/s762/html/wp-includes/plugin.php(465): WP_Hook->do_action(Array) #5 /home/s762/html/wp-settings.php(374): do_action(‘plugins_loaded’) #6 /home/s762/html/wp-config.php(69): require_once(‘/home/s762/html. in /home/s762/html/wp-content/plugins/virgil-pure/admin/core/Core/CoreProtocol.php on line 76