[Plugin: WooCommerce] Unknown filter failing order retrieval

I have been working with a client to upload their WooCommerce orders and found that my code is failing. I am using the ruby woocommerce_api gem, and have verified that the key and secret I have work with a separate call.

The cause of the problem appears to be a filter in my call: filter[expand] => 'product'. A colleague of mine wrote this in and I can no longer reach out to him to ask him about it. I do not know what this filter does. After removing it everything seemed to work fine, but I want to make sure that it doesn’t have a vital function that I am not seeing.

The error I am receiving WITH the filter is FATAL ERROR: Call to a member function raw_price_filter() on a non-object in home/<shortened domain name>/domains/<domain name>/public_html/wp-content/plugins/woocommerce-multilingual/inc/class-wcml-woocommerce-rest-api-support.php on line 395.