Warning: Undefined array key 0 in class-wp-list-table.php on line 1308

[jakubmikita]

It's thrown while using $registrar->columns()->sortable() method.

Full warning:

Warning: Undefined array key 0 in /app/web/wp/wp-admin/includes/class-wp-list-table.php on line 1308

[jjgrainger]

Thanks @jakubmikita

Could you provide the code you were using and the WordPress version this was thrown in? This will help me to narrow down the issue here.

Thanks