Fatal error: Uncaught TypeError: array_merge(): Argument #3 must be of type array, null given in /srv/app/public/wp/wp-includes/widgets.php:1354
Stack trace:
#0 /srv/app/public/wp/wp-includes/widgets.php(1354): array_merge(Array, Array, NULL, NULL)
#1 /srv/app/public/wp/wp-includes/widgets.php(1299): retrieve_widgets(true)
#2 /srv/app/public/wp/wp-includes/class-wp-hook.php(326): _wp_sidebars_changed('')
#3 /srv/app/public/wp/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#4 /srv/app/public/wp/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#5 /srv/app/public/wp/wp-includes/theme.php(3504): do_action('after_switch_th...', '', Object(WP_Theme))
#6 /srv/app/public/wp/wp-includes/class-wp-hook.php(324): check_theme_switched('')
#7 /srv/app/public/wp/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#8 /srv/app/public/wp/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#9 /srv/app/public/wp/wp-settings.php(700): do_action('init')
#10 /srv/app/public/wp-config.php(31): require_once('/srv/app/public...')
#11 /srv/app/public/wp/wp-load.php(55): require_once('/srv/app/public...')
#12 /srv/app/public/wp/wp-blog-header.php(13): require_once('/srv/app/public...')
#13 /srv/app/public/index.php(17): require('/srv/app/public...')
#14 {main}
  thrown in /srv/app/public/wp/wp-includes/widgets.php on line 1354