subscribers.php Notice: Undefined index: action

Fixed an issue with the subscribers.php when clicking the filter button. It was displaying errors (i have debug mode on) that action and action2 had not been defined.

Notice: Undefined index: action in subscribers.php on line 40

From line 40 you need to add the isset($_POST[‘action’] test to avoid this error :

...elseif ( (isset($_POST['action']) && $_POST['action'] === 'delete') || ( isset($_POST['action2']) && $_POST['action2'] === 'delete') ) {
...
} elseif ( (isset($_POST['action']) && $_POST['action'] === 'toggle') || ( isset($_POST['action2']) && $_POST['action2'] === 'toggle') ) {
...

https://www.ads-software.com/plugins/subscribe2/