Undefined index: title

Notice: Undefined index: title in G:\Websites\affiliates\goedkopegereedschappen.nl\httpdocs\wp-content\plugins\advanced-woo-search\includes\widget.php on line 24

I’ve changed
$title = apply_filters(‘widget_title’,$instance[‘title’],$instance,$this->id_base);

in

$title = apply_filters(
‘widget_title’,
( ! empty( $instance[‘title’] ) ? $instance[‘title’] : ” ),
$instance,
$this->id_base );

Nice plugin!