PHP Fatal error: Cannot use empty array elements in arrays in CENSORED on line 180 [duplicate]

I was searching on stackoverflow about my problem but I didn't found any good answer.

I have this problem: When I try to run my code

PHP Fatal error: Cannot use empty array elements in arrays in CENSORED on line 180

I receive this error.

This is my array:

        $text = [
            'first' => $getTrans($lang, 'reloading_first')."\n",
            'second' => "\n".$getTrans($lang, 'reloading_users_getting')."\n",
            'terzo' => "‎  ".$getTrans($lang, 'reloading_users_getting')." ",
            'quarto'=> "‎  ".$getTrans($lang, 'reloading_admins_getting')." ",,
            'quinto' => "\n".$getTrans($lang, 'reloading_elaborating_list')."\n", ];

The line 180 is this:

'first' => $getTrans($lang, 'reloading_first')."\n",

Whereas $getTrans looks like this:

$getTrans = function($lang, $identifier) { 
    global $database; 
    $mammt = $database->prepare("SELECT * FROM translations WHERE language=? AND code=?"); 
    $mammt->execute([$lang, $identifier]);
    $trans = $mammt->fetch(PDO::FETCH_ASSOC)['translation'];
    if($trans == NULL){ 
        $mammt->execute(['italian', $identifier]);
        $trans = $mammt->fetch(PDO::FETCH_ASSOC)['translation'];
    }
    return $trans;
};