Plugin doesn’t work, throws an error

Unable to get Topics list from AWS SNS!
Error: Invalid handle provided

I found this part in the code, it looks like this

try {
        // get topic list
	$topicList = $client->listTopics(array(
	//'NextToken' => 'string',
));
} catch (Exception $ex) {
	echo "<div class='error notice'><p>Unable to get Topics list from AWS SNS! <br> Error: ".$ex->getMessage()."</p></div>";
	return;
}

If you remove this code, the plugin works, but in the “Select topic” field, I see a variable $topicName. How can I fixed this?