Hey there,
I recently started seeing this error: WARNING: wp-content/plugins/bb-plugin/classes/class-fl-builder.php:851 - in_array() expects parameter 2 to be array, null given require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/renderbox/page.php'), get_template_part, locate_template, load_template, require('/themes/renderbox/content-page.php'), do_action('storefront_page'), call_user_func_array, storefront_page_content, the_content, apply_filters('the_content'), call_user_func_array, FLBuilder::render_content, in_array
on pages using Beaver Builder.
I’ve tested and found this issue in 1.6.3.3 and 1.6.4.
WP Debug is set to false.
This occurs even when all other plugins are disabled. So I think BB is the culprit here.
This article seems to relate to the issue: https://wordpress.org/support/topic/notice-wp_widget-is-deprecated-since-version-430?replies=25
Not sure if that relates or helps.