Fatal error: Uncaught ArgumentCountError: Too few arguments to function WP_Widget::__construct(), 0 passed in /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-includes/class-wp-widget-factory.php on line 61 and at least 2 expected in /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-includes/class-wp-widget.php:162
Stack trace:
#0 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-includes/class-wp-widget-factory.php(61): WP_Widget->__construct()
#1 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-includes/widgets.php(115): WP_Widget_Factory->register('Twenty_Eleven_E...')
#2 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-content/themes/kungfuwp/functions.php(191): register_widget('Twenty_Eleven_E...')
#3 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-includes/class-wp-hook.php(303): twentyeleven_widgets_init('')
#4 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters(NULL, Array)
#5 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-includes/plugin.php(470): WP_Hook->do_action(Array)
#6 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-includes/widgets.php(1809): do_action('widgets_init')
#7 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-includes/class-wp-hook.php(303): wp_widgets_init('')
#8 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters(NULL, Array)
#9 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-includes/plugin.php(470): WP_Hook->do_action(Array)
#10 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-settings.php(578): do_action('init')
#11 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-config.php(102): require_once('/customers/1/4/...')
#12 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-load.php(50): require_once('/customers/1/4/...')
#13 /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-blog-header.php(13): require_once('/customers/1/4/...')
#14 /customers/1/4/c/kungfuhaarlem.com/httpd.www/index.php(17): require('/customers/1/4/...')
#15 {main}
  thrown in /customers/1/4/c/kungfuhaarlem.com/httpd.www/wp-includes/class-wp-widget.php on line 162