Accelerate theme and PHP 8.0

After upgrading from PHP 7.4 to PHP 8.0 I get the following error:

Fatal error: Uncaught ArgumentCountError: Too few arguments to function WP_Widget::__construct(), 0 passed in /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-includes/class-wp-widget-factory.php on line 61 and at least 2 expected in /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-includes/class-wp-widget.php:162 Stack trace: #0 /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-includes/class-wp-widget-factory.php(61): WP_Widget->__construct() #1 /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-includes/widgets.php(115): WP_Widget_Factory->register('NinetyAjaxLogin') #2 /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-content/plugins/sb-login/sb-login.php(126): register_widget('NinetyAjaxLogin') #3 /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-includes/class-wp-hook.php(303): nd_login_init('') #4 /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters(NULL, Array) #5 /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-includes/plugin.php(470): WP_Hook->do_action(Array) #6 /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-settings.php(578): do_action('init') #7 /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-config.php(89): require_once('/customers/a/7/...') #8 /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-load.php(50): require_once('/customers/a/7/...') #9 /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-blog-header.php(13): require_once('/customers/a/7/...') #10 /customers/a/7/9/kfak.dk/httpd.www/index.php(17): require('/customers/a/7/...') #11 {main} thrown in /customers/a/7/9/kfak.dk/httpd.www/ny_kfak/wp-includes/class-wp-widget.php on line 162

Any ideas on how to solve this?

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