Fatal error: Uncaught ArgumentCountError: Too few arguments to function WP_Widget::__construct(), 0 passed in /customers/3/4/e/pianofabriken.se/httpd.www/wp-includes/class-wp-widget-factory.php on line 62 and at least 2 expected in /customers/3/4/e/pianofabriken.se/httpd.www/wp-includes/class-wp-widget.php:163
Stack trace:
#0 /customers/3/4/e/pianofabriken.se/httpd.www/wp-includes/class-wp-widget-factory.php(62): WP_Widget->__construct()
#1 /customers/3/4/e/pianofabriken.se/httpd.www/wp-includes/widgets.php(115): WP_Widget_Factory->register('Flickr_Widget_R...')
#2 /customers/3/4/e/pianofabriken.se/httpd.www/wp-content/themes/Backstreet/panel/widgets/flickr-widget.php(50): register_widget('Flickr_Widget_R...')
#3 /customers/3/4/e/pianofabriken.se/httpd.www/wp-content/themes/Backstreet/functions.php(88): include_once('/customers/3/4/...')
#4 /customers/3/4/e/pianofabriken.se/httpd.www/wp-settings.php(585): include('/customers/3/4/...')
#5 /customers/3/4/e/pianofabriken.se/httpd.www/wp-config.php(86): require_once('/customers/3/4/...')
#6 /customers/3/4/e/pianofabriken.se/httpd.www/wp-load.php(50): require_once('/customers/3/4/...')
#7 /customers/3/4/e/pianofabriken.se/httpd.www/wp-blog-header.php(13): require_once('/customers/3/4/...')
#8 /customers/3/4/e/pianofabriken.se/httpd.www/index.php(17): require('/customers/3/4/...')
#9 {main}
  thrown in /customers/3/4/e/pianofabriken.se/httpd.www/wp-includes/class-wp-widget.php on line 163