Multiple warnings in WordPress 4.9.1

Seeing a lot of warnings such as

Warning: in_array() expects parameter 2 to be array, null given in /var/www/html/wp-content/plugins/seo-optimized-share-buttons/simple-social-share-buttons.php on line 173

Warning: Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/seo-optimized-share-buttons/inc/backend/main-page.php on line 46

They appear on pages and in admin area if wp_debug is set to true.