Array Key Error after 2.6.1 Update

After updating the plugin from version 2.5.9 to 2.6.1, I am receiving an error in our error tracking software. The error is as follows:

Undefined array key "mode"

The error is caused by line 2359 in /modules/woo-filters/mod.php

public function render( $params ) {

		$p = array(

			'id' => ( isset($params['id']) ? (int) $params['id'] : 0 ),

			'mode' => ( 'widget' == $params['mode'] ? 'widget' : '' ),

		);

		return $this->getView()->renderHtml( $p );

	}