Error 500 with Relevanssi 3.5.9.1

[Web1776]

I started getting an Error 500 on the autocompleteCallback AJAX request after updating to Relevanssi 3.5.9.1

I am using version 2.1.16 of SearchAutocomplete

The portion of searchautocomplete.php that passes the query to Relevanssi (line 129) does not appear to pass a WP_Query object to the relevanssi_do_query() as noted in the Relevanssi documentation: https://www.relevanssi.com/knowledge-base/relevanssi_do_query/

I added the following at line 130 of searchautocomplete.php and the issue appears to be solved:

$query = new WP_Query();