PHP Warning: Undefined array key

The above warning was in the wp-debug file, but nothing is showing in the panel. Assuming that this may be thrown by another plugin, I have gone through the site and the only issue I found is that if I try to open Customise, I get a fatal error:

Fatal error: Uncaught Error: strnatcasecmp(): Argument #1 ($string1) must be of type string, array given
in /home/u675030324/domains/chronographia.eu/public_html/wp-includes/class-wp-customize-widgets.php on line 1

Call stack:

strnatcasecmp()
wp-includes/class-wp-customize-widgets.php:1131

WP_Customize_Widgets::_sort_name_callback()

usort()
wp-includes/class-wp-customize-widgets.php:1050

WP_Customize_Widgets::get_available_widgets()
wp-includes/class-wp-customize-widgets.php:714

WP_Customize_Widgets::enqueue_scripts()
wp-includes/class-wp-hook.php:308

WP_Hook::apply_filters()
wp-includes/class-wp-hook.php:332`

WP_Hook::do_action()
wp-includes/plugin.php:517

do_action()
wp-admin/customize.php:1

Query Monitor

• This reply was modified 3 years ago by Malae.